diff --git a/hphp/runtime/base/preg.cpp b/hphp/runtime/base/preg.cpp
index 89e91ee42..2001f8658 100644
--- a/hphp/runtime/base/preg.cpp
+++ b/hphp/runtime/base/preg.cpp
@@ -329,14 +329,12 @@ static pcre* pcre_get_compiled_regex(CStrRef regex, pcre_extra **extra,
 
 static inline void add_offset_pair(Variant &result, CStrRef str, int offset,
                                    const char *name) {
-  Array match_pair;
-  match_pair.append(str);
-  match_pair.append(offset);
-
-  if (name) {
-    result.set(name, match_pair);
-  }
-  result.append(match_pair);
+  ArrayInit match_pair(2);
+  match_pair.set(str);
+  match_pair.set(offset);
+  Variant match_pair_v = match_pair.toVariant();
+  if (name) result.set(String(name), match_pair_v);
+  result.append(match_pair_v);
 }
 
 static inline bool pcre_need_log_error(int pcre_code) {
@@ -633,7 +631,7 @@ static Variant preg_match_impl(CStrRef pattern, CStrRef subject,
               String value(stringlist[i], offsets[(i<<1)+1] - offsets[i<<1],
                            CopyString);
               if (subpat_names[i]) {
-                result_set.set(subpat_names[i], value);
+                result_set.set(String(subpat_names[i]), value);
               }
               result_set.append(value);
             }
@@ -654,7 +652,7 @@ static Variant preg_match_impl(CStrRef pattern, CStrRef subject,
             String value(stringlist[i], offsets[(i<<1)+1] - offsets[i<<1],
                          CopyString);
             if (subpat_names[i]) {
-              subpats->set(subpat_names[i], value);
+              subpats->set(String(subpat_names[i]), value);
             }
             subpats->append(value);
           }
@@ -698,7 +696,7 @@ static Variant preg_match_impl(CStrRef pattern, CStrRef subject,
   if (subpats && global && subpats_order == PREG_PATTERN_ORDER) {
     for (i = 0; i < num_subpats; i++) {
       if (subpat_names[i]) {
-        subpats->set(subpat_names[i], match_sets[i]);
+        subpats->set(String(subpat_names[i]), match_sets[i]);
       }
       subpats->append(match_sets[i]);
     }
diff --git a/hphp/runtime/base/program_functions.cpp b/hphp/runtime/base/program_functions.cpp
index 27a295166..abfade84e 100644
--- a/hphp/runtime/base/program_functions.cpp
+++ b/hphp/runtime/base/program_functions.cpp
@@ -128,7 +128,7 @@ static void process_cmd_arguments(int argc, char **argv) {
   SystemGlobals *g = (SystemGlobals *)get_global_variables();
   g->GV(argc) = argc;
   for (int i = 0; i < argc; i++) {
-    g->GV(argv).lvalAt() = argv[i];
+    g->GV(argv).lvalAt() = String(argv[i]);
   }
 }
 
@@ -439,6 +439,21 @@ void handle_destructor_exception(const char* situation) {
   }
 }
 
+static const StaticString
+  s_HPHP("HPHP"),
+  s_HHVM("HHVM"),
+  s_HHVM_JIT("HHVM_JIT"),
+  s_REQUEST_START_TIME("REQUEST_START_TIME"),
+  s_REQUEST_TIME("REQUEST_TIME"),
+  s_DOCUMENT_ROOT("DOCUMENT_ROOT"),
+  s_SCRIPT_FILENAME("SCRIPT_FILENAME"),
+  s_SCRIPT_NAME("SCRIPT_NAME"),
+  s_PHP_SELF("PHP_SELF"),
+  s_argc("argc"),
+  s_argv("argv"),
+  s_PWD("PWD"),
+  s_HOSTNAME("HOSTNAME");
+
 void execute_command_line_begin(int argc, char **argv, int xhprof) {
   StackTraceNoHeap::AddExtraLogging("ThreadType", "CLI");
   string args;
@@ -455,10 +470,10 @@ void execute_command_line_begin(int argc, char **argv, int xhprof) {
   SystemGlobals *g = (SystemGlobals *)get_global_variables();
 
   process_env_variables(g->GV(_ENV));
-  g->GV(_ENV).set("HPHP", 1);
-  g->GV(_ENV).set("HHVM", 1);
+  g->GV(_ENV).set(s_HPHP, 1);
+  g->GV(_ENV).set(s_HHVM, 1);
   if (RuntimeOption::EvalJit) {
-    g->GV(_ENV).set("HHVM_JIT", 1);
+    g->GV(_ENV).set(s_HHVM_JIT, 1);
   }
 
   process_cmd_arguments(argc, argv);
@@ -466,18 +481,18 @@ void execute_command_line_begin(int argc, char **argv, int xhprof) {
   Variant &server = g->GV(_SERVER);
   process_env_variables(server);
   time_t now = time(nullptr);
-  server.set("REQUEST_START_TIME", now);
-  server.set("REQUEST_TIME", now);
-  server.set("DOCUMENT_ROOT", "");
-  server.set("SCRIPT_FILENAME", argv[0]);
-  server.set("SCRIPT_NAME", argv[0]);
-  server.set("PHP_SELF", argv[0]);
-  server.set("argv", g->GV(argv));
-  server.set("argc", g->GV(argc));
-  server.set("PWD", g_context->getCwd());
+  server.set(s_REQUEST_START_TIME, now);
+  server.set(s_REQUEST_TIME, now);
+  server.set(s_DOCUMENT_ROOT, empty_string);
+  server.set(s_SCRIPT_FILENAME, argv[0]);
+  server.set(s_SCRIPT_NAME, argv[0]);
+  server.set(s_PHP_SELF, argv[0]);
+  server.set(s_argv, g->GV(argv));
+  server.set(s_argc, g->GV(argc));
+  server.set(s_PWD, g_context->getCwd());
   char hostname[1024];
   if (!gethostname(hostname, 1024)) {
-    server.set("HOSTNAME", String(hostname, CopyString));
+    server.set(s_HOSTNAME, String(hostname, CopyString));
   }
 
   for(std::map<string,string>::iterator it =
diff --git a/hphp/runtime/base/server/http_protocol.cpp b/hphp/runtime/base/server/http_protocol.cpp
index 040e981aa..6b2718d03 100644
--- a/hphp/runtime/base/server/http_protocol.cpp
+++ b/hphp/runtime/base/server/http_protocol.cpp
@@ -73,6 +73,51 @@ const VirtualHost *HttpProtocol::GetVirtualHost(Transport *transport) {
   return VirtualHost::GetCurrent();
 }
 
+static const StaticString
+  s_REQUEST_START_TIME("REQUEST_START_TIME"),
+  s_HPHP("HPHP"),
+  s_HHVM("HHVM"),
+  s_HHVM_JIT("HHVM_JIT"),
+  s_HPHP_SERVER("HPHP_SERVER"),
+  s_HPHP_HOTPROFILER("HPHP_HOTPROFILER"),
+  s_HTTP_HOST("HTTP_HOST"),
+  s_CONTENT_TYPE("CONTENT_TYPE"),
+  s_CONTENT_LENGTH("CONTENT_LENGTH"),
+  s_PHP_AUTH_USER("PHP_AUTH_USER"),
+  s_PHP_AUTH_PW("PHP_AUTH_PW"),
+  s_REQUEST_URI("REQUEST_URI"),
+  s_SCRIPT_URL("SCRIPT_URL"),
+  s_SCRIPT_URI("SCRIPT_URI"),
+  s_SCRIPT_NAME("SCRIPT_NAME"),
+  s_PHP_SELF("PHP_SELF"),
+  s_SCRIPT_FILENAME("SCRIPT_FILENAME"),
+  s_PATH_TRANSLATED("PATH_TRANSLATED"),
+  s_PATH_INFO("PATH_INFO"),
+  s_argc("argc"),
+  s_argv("argv"),
+  s_GATEWAY_INTERFACE("GATEWAY_INTERFACE"),
+  s_CGI_1_1("CGI/1.1"),
+  s_SERVER_ADDR("SERVER_ADDR"),
+  s_SERVER_NAME("SERVER_NAME"),
+  s_SERVER_PORT("SERVER_PORT"),
+  s_SERVER_SOFTWARE("SERVER_SOFTWARE"),
+  s_SERVER_PROTOCOL("SERVER_PROTOCOL"),
+  s_SERVER_ADMIN("SERVER_ADMIN"),
+  s_SERVER_SIGNATURE("SERVER_SIGNATURE"),
+  s_REQUEST_METHOD("REQUEST_METHOD"),
+  s_GET("GET"),
+  s_HEAD("HEAD"),
+  s_POST("POST"),
+  s_HTTPS("HTTPS"),
+  s_1("1"),
+  s_REQUEST_TIME("REQUEST_TIME"),
+  s_QUERY_STRING("QUERY_STRING"),
+  s_REMOTE_ADDR("REMOTE_ADDR"),
+  s_REMOTE_HOST("REMOTE_HOST"),
+  s_REMOTE_PORT("REMOTE_PORT"),
+  s_DOCUMENT_ROOT("DOCUMENT_ROOT"),
+  s_THREAD_TYPE("THREAD_TYPE");
+
 /**
  * PHP has "EGPCS" processing order of these global variables, and this
  * order is important in preparing $_REQUEST that needs to know which to
@@ -85,21 +130,21 @@ void HttpProtocol::PrepareSystemVariables(Transport *transport,
   const VirtualHost *vhost = VirtualHost::GetCurrent();
 
   Variant &server = g->GV(_SERVER);
-  server.set("REQUEST_START_TIME", time(nullptr));
+  server.set(s_REQUEST_START_TIME, time(nullptr));
 
   // $_ENV
   process_env_variables(g->GV(_ENV));
-  g->GV(_ENV).set("HPHP", 1);
-  g->GV(_ENV).set("HHVM", 1);
+  g->GV(_ENV).set(s_HPHP, 1);
+  g->GV(_ENV).set(s_HHVM, 1);
   if (RuntimeOption::EvalJit) {
-    g->GV(_ENV).set("HHVM_JIT", 1);
+    g->GV(_ENV).set(s_HHVM_JIT, 1);
   }
 
   bool isServer = RuntimeOption::serverExecutionMode();
   if (isServer) {
-    g->GV(_ENV).set("HPHP_SERVER", 1);
+    g->GV(_ENV).set(s_HPHP_SERVER, 1);
 #ifdef HOTPROFILER
-    g->GV(_ENV).set("HPHP_HOTPROFILER", 1);
+    g->GV(_ENV).set(s_HPHP_HOTPROFILER, 1);
 #endif
   }
 
@@ -235,7 +280,7 @@ void HttpProtocol::PrepareSystemVariables(Transport *transport,
   String hostName(VirtualHost::GetCurrent()->serverName(host));
   string hostHeader(host);
   if (hostHeader.empty()) {
-    server.set("HTTP_HOST", hostName);
+    server.set(s_HTTP_HOST, hostName);
     StackTraceNoHeap::AddExtraLogging("Server", hostName.data());
   } else {
     StackTraceNoHeap::AddExtraLogging("Server", hostHeader.c_str());
@@ -251,10 +296,10 @@ void HttpProtocol::PrepareSystemVariables(Transport *transport,
 
   // APE sets CONTENT_TYPE and CONTENT_LENGTH without HTTP_
   if (!contentType.empty()) {
-    server.set("CONTENT_TYPE", String(contentType));
+    server.set(s_CONTENT_TYPE, String(contentType));
   }
   if (!contentLength.empty()) {
-    server.set("CONTENT_LENGTH", String(contentLength));
+    server.set(s_CONTENT_LENGTH, String(contentLength));
   }
 
   // APE processes Authorization: Basic into PHP_AUTH_USER and PHP_AUTH_PW
@@ -267,14 +312,14 @@ void HttpProtocol::PrepareSystemVariables(Transport *transport,
         StringUtil::Base64Decode(String(authorization.c_str() + 6));
       int colonPos = decodedAuth.find(':');
       if (colonPos != String::npos) {
-        server.set("PHP_AUTH_USER", decodedAuth.substr(0, colonPos));
-        server.set("PHP_AUTH_PW", decodedAuth.substr(colonPos + 1));
+        server.set(s_PHP_AUTH_USER, decodedAuth.substr(0, colonPos));
+        server.set(s_PHP_AUTH_PW, decodedAuth.substr(colonPos + 1));
       }
     }
   }
 
-  server.set("REQUEST_URI", String(transport->getUrl(), CopyString));
-  server.set("SCRIPT_URL", r.originalURL());
+  server.set(s_REQUEST_URI, String(transport->getUrl(), CopyString));
+  server.set(s_SCRIPT_URL, r.originalURL());
   String prefix(transport->isSSL() ? "https://" : "http://");
   String port_suffix("");
 
@@ -282,7 +327,7 @@ void HttpProtocol::PrepareSystemVariables(Transport *transport,
   if (!transport->isSSL() && RuntimeOption::ServerPort != 80) {
     port_suffix = ":" + RuntimeOption::ServerPort;
   }
-  server.set("SCRIPT_URI",
+  server.set(s_SCRIPT_URI,
              String(prefix + (hostHeader.empty() ? hostName + port_suffix :
                               String(hostHeader)) + r.originalURL()));
 
@@ -301,57 +346,57 @@ void HttpProtocol::PrepareSystemVariables(Transport *transport,
       }
       name += String(RuntimeOption::DefaultDocument);
     }
-    server.set("SCRIPT_NAME", name);
+    server.set(s_SCRIPT_NAME, name);
   } else {
-    server.set("SCRIPT_NAME", r.resolvedURL());
+    server.set(s_SCRIPT_NAME, r.resolvedURL());
   }
   if (!r.rewritten() && r.pathInfo().empty()) {
-    server.set("PHP_SELF", r.resolvedURL());
+    server.set(s_PHP_SELF, r.resolvedURL());
   } else {
     // when URL is rewritten, or pathinfo is not empty, use original URL
-    server.set("PHP_SELF", r.originalURL());
+    server.set(s_PHP_SELF, r.originalURL());
   }
 
-  server.set("SCRIPT_FILENAME", r.absolutePath());
+  server.set(s_SCRIPT_FILENAME, r.absolutePath());
   if (r.pathInfo().empty()) {
-    server.set("PATH_TRANSLATED", r.absolutePath());
+    server.set(s_PATH_TRANSLATED, r.absolutePath());
   } else {
-    server.set("PATH_TRANSLATED",
+    server.set(s_PATH_TRANSLATED,
                String(vhost->getDocumentRoot() + r.pathInfo().data()));
-    server.set("PATH_INFO", r.pathInfo());
+    server.set(s_PATH_INFO, r.pathInfo());
   }
 
-  server.set("argv", r.queryString());
-  server.set("argc", 0);
-  server.set("GATEWAY_INTERFACE", "CGI/1.1");
-  server.set("SERVER_ADDR", String(RuntimeOption::ServerPrimaryIP));
-  server.set("SERVER_NAME", hostName);
-  server.set("SERVER_PORT", RuntimeOption::ServerPort);
-  server.set("SERVER_SOFTWARE", "HPHP");
-  server.set("SERVER_PROTOCOL", "HTTP/" + transport->getHTTPVersion());
-  server.set("SERVER_ADMIN", "");
-  server.set("SERVER_SIGNATURE", "");
+  server.set(s_argv, r.queryString());
+  server.set(s_argc, 0);
+  server.set(s_GATEWAY_INTERFACE, s_CGI_1_1);
+  server.set(s_SERVER_ADDR, String(RuntimeOption::ServerPrimaryIP));
+  server.set(s_SERVER_NAME, hostName);
+  server.set(s_SERVER_PORT, RuntimeOption::ServerPort);
+  server.set(s_SERVER_SOFTWARE, s_HPHP);
+  server.set(s_SERVER_PROTOCOL, "HTTP/" + transport->getHTTPVersion());
+  server.set(s_SERVER_ADMIN, empty_string);
+  server.set(s_SERVER_SIGNATURE, empty_string);
   switch (transport->getMethod()) {
-  case Transport::GET:  server.set("REQUEST_METHOD", "GET");  break;
-  case Transport::HEAD: server.set("REQUEST_METHOD", "HEAD"); break;
+  case Transport::GET:  server.set(s_REQUEST_METHOD, s_GET);  break;
+  case Transport::HEAD: server.set(s_REQUEST_METHOD, s_HEAD); break;
   case Transport::POST:
     if (transport->getExtendedMethod() == nullptr) {
-      server.set("REQUEST_METHOD", "POST");
+      server.set(s_REQUEST_METHOD, s_POST);
     } else {
-      server.set("REQUEST_METHOD", transport->getExtendedMethod());
+      server.set(s_REQUEST_METHOD, transport->getExtendedMethod());
     }
     break;
-  default:              server.set("REQUEST_METHOD", "");     break;
+  default:              server.set(s_REQUEST_METHOD, empty_string);     break;
   }
-  server.set("HTTPS", transport->isSSL() ? "1" : "");
-  server.set("REQUEST_TIME", time(nullptr));
-  server.set("QUERY_STRING", r.queryString());
+  server.set(s_HTTPS, transport->isSSL() ? s_1 : empty_string);
+  server.set(s_REQUEST_TIME, time(nullptr));
+  server.set(s_QUERY_STRING, r.queryString());
 
-  server.set("REMOTE_ADDR", String(transport->getRemoteHost(), CopyString));
-  server.set("REMOTE_HOST", ""); // I don't think we need to nslookup
-  server.set("REMOTE_PORT", transport->getRemotePort());
+  server.set(s_REMOTE_ADDR, String(transport->getRemoteHost(), CopyString));
+  server.set(s_REMOTE_HOST, empty_string); // I don't think we need to nslookup
+  server.set(s_REMOTE_PORT, transport->getRemotePort());
 
-  server.set("DOCUMENT_ROOT", String(vhost->getDocumentRoot()));
+  server.set(s_DOCUMENT_ROOT, String(vhost->getDocumentRoot()));
 
   for (map<string, string>::const_iterator iter =
          RuntimeOption::ServerVariables.begin();
@@ -367,7 +412,7 @@ void HttpProtocol::PrepareSystemVariables(Transport *transport,
   sri.setServerVariables(server);
 
   const char *threadType = transport->getThreadTypeName();
-  server.set("THREAD_TYPE", threadType);
+  server.set(s_THREAD_TYPE, threadType);
   StackTraceNoHeap::AddExtraLogging("ThreadType", threadType);
 }
 
diff --git a/hphp/runtime/base/server/rpc_request_handler.cpp b/hphp/runtime/base/server/rpc_request_handler.cpp
index 23bf1d300..97ffad4d8 100644
--- a/hphp/runtime/base/server/rpc_request_handler.cpp
+++ b/hphp/runtime/base/server/rpc_request_handler.cpp
@@ -152,8 +152,10 @@ void RPCRequestHandler::handleRequest(Transport *transport) {
   HttpProtocol::ClearRecord(ret, tmpfile);
 }
 
-static const StaticString s_output("output");
-static const StaticString s_return("return");
+static const StaticString
+  s_output("output"),
+  s_return("return"),
+  s_HPHP_RPC("HPHP_RPC");
 
 bool RPCRequestHandler::executePHPFunction(Transport *transport,
                                            SourceRootInfo &sourceRootInfo) {
@@ -166,7 +168,7 @@ bool RPCRequestHandler::executePHPFunction(Transport *transport,
     RequestURI reqURI(rpcFunc);
     HttpProtocol::PrepareSystemVariables(transport, reqURI, sourceRootInfo);
     SystemGlobals *g = (SystemGlobals*)get_global_variables();
-    g->GV(_ENV).set("HPHP_RPC", 1);
+    g->GV(_ENV).set(s_HPHP_RPC, 1);
   }
 
   bool isFile = rpcFunc.rfind('.') != string::npos;
diff --git a/hphp/runtime/base/server/source_root_info.cpp b/hphp/runtime/base/server/source_root_info.cpp
index fc4f0d659..2a87f5712 100644
--- a/hphp/runtime/base/server/source_root_info.cpp
+++ b/hphp/runtime/base/server/source_root_info.cpp
@@ -247,10 +247,12 @@ string SourceRootInfo::path() const {
   }
 }
 
+static const StaticString s_PHP_ROOT("PHP_ROOT");
+
 string& SourceRootInfo::initPhpRoot() {
   SystemGlobals *g = (SystemGlobals*)get_global_variables();
   Variant &server = g->GV(_SERVER);
-  Variant v = server.rvalAt("PHP_ROOT");
+  Variant v = server.rvalAt(s_PHP_ROOT);
   if (v.isString()) {
     *s_phproot.getCheck() = string(v.asCStrRef().data()) + string("/");
   } else {
diff --git a/hphp/runtime/base/server/xbox_server.cpp b/hphp/runtime/base/server/xbox_server.cpp
index 3c6ebf8e3..8b8b0893c 100644
--- a/hphp/runtime/base/server/xbox_server.cpp
+++ b/hphp/runtime/base/server/xbox_server.cpp
@@ -31,7 +31,7 @@ namespace HPHP {
 
 class XboxTransport : public Transport, public Synchronizable {
 public:
-  XboxTransport(CStrRef message, CStrRef reqInitDoc = "")
+  explicit XboxTransport(CStrRef message, CStrRef reqInitDoc = "")
       : m_refCount(0), m_done(false), m_code(0) {
     gettime(CLOCK_MONOTONIC, &m_queueTime);
 
@@ -239,6 +239,11 @@ static bool isLocalHost(CStrRef host) {
   return host.empty() || host == "localhost" || host == "127.0.0.1";
 }
 
+static const StaticString
+  s_code("code"),
+  s_response("response"),
+  s_error("error");
+
 bool XboxServer::SendMessage(CStrRef message, Variant &ret, int timeout_ms,
                              CStrRef host /* = "localhost" */) {
   if (isLocalHost(host)) {
@@ -262,11 +267,11 @@ bool XboxServer::SendMessage(CStrRef message, Variant &ret, int timeout_ms,
     job->decRefCount(); // i'm done with this job
 
     if (code > 0) {
-      ret.set("code", code);
+      ret.set(s_code, code);
       if (code == 200) {
-        ret.set("response", unserialize_from_string(response));
+        ret.set(s_response, unserialize_from_string(response));
       } else {
-        ret.set("error", response);
+        ret.set(s_error, response);
       }
       return true;
     }
@@ -294,17 +299,17 @@ bool XboxServer::SendMessage(CStrRef message, Variant &ret, int timeout_ms,
         int len = 0;
         char *response = http->recv(len);
         String sresponse(response, len, AttachString);
-        ret.set("code", code);
+        ret.set(s_code, code);
         if (code == 200) {
-          ret.set("response", unserialize_from_string(sresponse));
+          ret.set(s_response, unserialize_from_string(sresponse));
         } else {
-          ret.set("error", sresponse);
+          ret.set(s_error, sresponse);
         }
         return true;
       }
       // code wasn't correctly set by http client, treat it as not found
-      ret.set("code", 404);
-      ret.set("error", "http client failed");
+      ret.set(s_code, 404);
+      ret.set(s_error, "http client failed");
     }
   }
 
diff --git a/hphp/runtime/base/type_variant.cpp b/hphp/runtime/base/type_variant.cpp
index 525fbdbd5..415f8b3ae 100644
--- a/hphp/runtime/base/type_variant.cpp
+++ b/hphp/runtime/base/type_variant.cpp
@@ -291,10 +291,6 @@ HOT_FUNC IMPLEMENT_SET(bool, m_type = KindOfBoolean; m_data.num = v)
 IMPLEMENT_SET(int, m_type = KindOfInt64; m_data.num = v)
 HOT_FUNC IMPLEMENT_SET(int64_t, m_type = KindOfInt64; m_data.num = v)
 IMPLEMENT_SET(double, m_type = KindOfDouble; m_data.dbl = v)
-IMPLEMENT_SET(litstr,
-              m_type = KindOfString;
-              m_data.pstr = NEW(StringData)(v);
-              m_data.pstr->incRefCount())
 IMPLEMENT_SET(const StaticString&,
               StringData* s = v.get();
               assert(s);
@@ -1279,7 +1275,7 @@ Variant &Variant::operator++() {
   case KindOfString:
     {
       if (getStringData()->empty()) {
-        set("1");
+        set(s_1);
       } else {
         int64_t lval; double dval;
         DataType ret = convertToNumeric(&lval, &dval);
@@ -1914,11 +1910,6 @@ Variant Variant::rvalAtHelper(int64_t offset, ACCESSPARAMS_IMPL) const {
   return null_variant;
 }
 
-Variant Variant::rvalAt(litstr offset, ACCESSPARAMS_IMPL) const {
-  String key(offset);
-  return rvalAt(key, flags);
-}
-
 Variant Variant::rvalAt(CStrRef offset, ACCESSPARAMS_IMPL) const {
   if (m_type == KindOfArray) {
     bool error = flags & AccessFlags::Error;
@@ -2068,11 +2059,6 @@ CVarRef Variant::rvalRef(double offset, CVarRef tmp, ACCESSPARAMS_IMPL) const {
   return rvalRefHelper(offset, tmp, flags);
 }
 
-CVarRef Variant::rvalRef(litstr offset, CVarRef tmp, ACCESSPARAMS_IMPL) const {
-  String key(offset);
-  return rvalRef(key, tmp, flags);
-}
-
 CVarRef Variant::rvalRef(CStrRef offset, CVarRef tmp, ACCESSPARAMS_IMPL) const {
   if (m_type == KindOfArray) {
     bool error = flags & AccessFlags::Error;
@@ -2252,10 +2238,6 @@ Variant &Variant::lvalAt(int64_t   key, ACCESSPARAMS_IMPL) {
 Variant &Variant::lvalAt(double  key, ACCESSPARAMS_IMPL) {
   return lvalAtImpl(key, flags);
 }
-Variant &Variant::lvalAt(litstr  ckey, ACCESSPARAMS_IMPL) {
-  String key(ckey);
-  return lvalAt(key, flags);
-}
 Variant &Variant::lvalAt(CStrRef key, ACCESSPARAMS_IMPL) {
   return lvalAtImpl<CStrRef>(key, flags);
 }
@@ -2272,10 +2254,6 @@ Variant &Variant::lvalRef(int64_t   key, Variant& tmp, ACCESSPARAMS_IMPL) {
 Variant &Variant::lvalRef(double  key, Variant& tmp, ACCESSPARAMS_IMPL) {
   return LvalAtImpl0(this, key, &tmp, false, flags);
 }
-Variant &Variant::lvalRef(litstr ckey, Variant& tmp, ACCESSPARAMS_IMPL) {
-  String key(ckey);
-  return lvalRef(key, tmp, flags);
-}
 Variant &Variant::lvalRef(CStrRef key, Variant& tmp, ACCESSPARAMS_IMPL) {
   return Variant::LvalAtImpl0<CStrRef>(this, key, &tmp, false, flags);
 }
diff --git a/hphp/runtime/base/type_variant.h b/hphp/runtime/base/type_variant.h
index efe79dffe..9058517ac 100644
--- a/hphp/runtime/base/type_variant.h
+++ b/hphp/runtime/base/type_variant.h
@@ -802,7 +802,7 @@ class Variant : private TypedValue {
     return rvalAtHelper(offset, flags);
   }
   Variant rvalAt(double offset, ACCESSPARAMS_DECL) const;
-  Variant rvalAt(litstr offset, ACCESSPARAMS_DECL) const;
+  Variant rvalAt(litstr offset, ACCESSPARAMS_DECL) const = delete;
   Variant rvalAt(CStrRef offset, ACCESSPARAMS_DECL) const;
   Variant rvalAt(CVarRef offset, ACCESSPARAMS_DECL) const;
 
@@ -819,7 +819,7 @@ class Variant : private TypedValue {
     return rvalRefHelper(offset, tmp, flags);
   }
   CVarRef rvalRef(double offset, CVarRef tmp, ACCESSPARAMS_DECL) const;
-  CVarRef rvalRef(litstr offset, CVarRef tmp, ACCESSPARAMS_DECL) const;
+  CVarRef rvalRef(litstr offset, CVarRef tmp, ACCESSPARAMS_DECL) const = delete;
   CVarRef rvalRef(CStrRef offset, CVarRef tmp, ACCESSPARAMS_DECL) const;
   CVarRef rvalRef(CVarRef offset, CVarRef tmp, ACCESSPARAMS_DECL) const;
 
@@ -873,14 +873,14 @@ class Variant : private TypedValue {
   Variant &lvalAt(int     key, ACCESSPARAMS_DECL);
   Variant &lvalAt(int64_t   key, ACCESSPARAMS_DECL);
   Variant &lvalAt(double  key, ACCESSPARAMS_DECL);
-  Variant &lvalAt(litstr  key, ACCESSPARAMS_DECL);
+  Variant &lvalAt(litstr  key, ACCESSPARAMS_DECL) = delete;
   Variant &lvalAt(CStrRef key, ACCESSPARAMS_DECL);
   Variant &lvalAt(CVarRef key, ACCESSPARAMS_DECL);
 
   Variant &lvalRef(int     key, Variant& tmp, ACCESSPARAMS_DECL);
   Variant &lvalRef(int64_t   key, Variant& tmp, ACCESSPARAMS_DECL);
   Variant &lvalRef(double  key, Variant& tmp, ACCESSPARAMS_DECL);
-  Variant &lvalRef(litstr  key, Variant& tmp, ACCESSPARAMS_DECL);
+  Variant &lvalRef(litstr  key, Variant& tmp, ACCESSPARAMS_DECL) = delete;
   Variant &lvalRef(CStrRef key, Variant& tmp, ACCESSPARAMS_DECL);
   Variant &lvalRef(CVarRef key, Variant& tmp, ACCESSPARAMS_DECL);
 
@@ -907,9 +907,7 @@ class Variant : private TypedValue {
   CVarRef set(int     key, CVarRef v) { return set((int64_t)key, v); }
   CVarRef set(int64_t   key, CVarRef v);
   CVarRef set(double  key, CVarRef v);
-  CVarRef set(litstr  key, CVarRef v, bool isString = false) {
-    return set(String(key), v, isString);
-  }
+  CVarRef set(litstr  key, CVarRef v, bool isString = false) = delete;
   CVarRef set(CStrRef key, CVarRef v, bool isString = false);
   CVarRef set(CVarRef key, CVarRef v);
 
@@ -918,18 +916,14 @@ class Variant : private TypedValue {
   CVarRef setRef(int     key, CVarRef v) { return setRef((int64_t)key, v); }
   CVarRef setRef(int64_t   key, CVarRef v);
   CVarRef setRef(double  key, CVarRef v);
-  CVarRef setRef(litstr  key, CVarRef v, bool isString = false) {
-    return setRef(String(key), v, isString);
-  }
+  CVarRef setRef(litstr  key, CVarRef v, bool isString = false) = delete;
   CVarRef setRef(CStrRef key, CVarRef v, bool isString = false);
   CVarRef setRef(CVarRef key, CVarRef v);
 
   CVarRef set(int     key, RefResult v) { return setRef(key, variant(v)); }
   CVarRef set(int64_t   key, RefResult v) { return setRef(key, variant(v)); }
   CVarRef set(double  key, RefResult v) { return setRef(key, variant(v)); }
-  CVarRef set(litstr  key, RefResult v, bool isString = false) {
-    return setRef(key, variant(v), isString);
-  }
+  CVarRef set(litstr  key, RefResult v, bool isString = false) = delete;
   CVarRef set(CStrRef key, RefResult v, bool isString = false) {
     return setRef(key, variant(v), isString);
   }
@@ -941,9 +935,7 @@ class Variant : private TypedValue {
   void remove(int     key) { removeImpl((int64_t)key);}
   void remove(int64_t   key) { removeImpl(key);}
   void remove(double  key) { removeImpl(key);}
-  void remove(litstr  key, bool isString = false) {
-    remove(String(key), isString);
-  }
+  void remove(litstr  key, bool isString = false) = delete;
   void remove(CStrRef key, bool isString = false) {
     removeImpl(key, isString);
   }
@@ -1129,7 +1121,7 @@ class Variant : private TypedValue {
   CVarRef set(int     v);
   CVarRef set(int64_t   v);
   CVarRef set(double  v);
-  CVarRef set(litstr  v);
+  CVarRef set(litstr  v) = delete;
   CVarRef set(const std::string & v) {
     return set(String(v));
   }
@@ -1449,8 +1441,8 @@ public:
     return asVariant()->isNull();
   }
 private:
-  /* implicit */ VarNR(litstr  v); // not implemented
-  /* implicit */ VarNR(const std::string & v); // not implemented
+  /* implicit */ VarNR(litstr  v) = delete;
+  /* implicit */ VarNR(const std::string & v) = delete;
 
   void init(DataType dt) {
     m_type = dt;
diff --git a/hphp/runtime/ext/ext_function.cpp b/hphp/runtime/ext/ext_function.cpp
index 1f1e62cf0..331d5e4f9 100644
--- a/hphp/runtime/ext/ext_function.cpp
+++ b/hphp/runtime/ext/ext_function.cpp
@@ -49,6 +49,10 @@ bool f_function_exists(CStrRef function_name, bool autoload /* = true */) {
      function_exists(function_name));
 }
 
+static const StaticString
+  s__invoke("__invoke"),
+  s_Closure__invoke("Closure::__invoke");
+
 bool f_is_callable(CVarRef v, bool syntax /* = false */,
                    VRefParam name /* = null */) {
   bool ret = true;
@@ -107,13 +111,11 @@ bool f_is_callable(CVarRef v, bool syntax /* = false */,
 
   if (Variant::GetAccessorType(tv_func) == KindOfObject) {
     ObjectData *d = Variant::GetObjectData(tv_func);
-    static const StringData* sd__invoke
-      = StringData::GetStaticString("__invoke");
-    const Func* invoke = d->getVMClass()->lookupMethod(sd__invoke);
+    const Func* invoke = d->getVMClass()->lookupMethod(s__invoke.get());
     if (name.isReferenced()) {
       if (d->instanceof(c_Closure::s_cls)) {
         // Hack to stop the mangled name from showing up
-        name = "Closure::__invoke";
+        name = s_Closure__invoke;
       } else {
         name = d->o_getClassName() + "::__invoke";
       }
@@ -124,7 +126,8 @@ bool f_is_callable(CVarRef v, bool syntax /* = false */,
   return false;
 }
 
-Variant f_call_user_func(int _argc, CVarRef function, CArrRef _argv /* = null_array */) {
+Variant f_call_user_func(int _argc, CVarRef function,
+                         CArrRef _argv /* = null_array */) {
   return vm_call_user_func(function, _argv);
 }
 
@@ -165,9 +168,9 @@ String f_call_user_func_serialized(CStrRef input) {
   Variant out;
   try {
     Variant in = unserialize_from_string(input);
-    out.set("ret", vm_call_user_func(in[s_func], in[s_args]));
+    out.set(s_ret, vm_call_user_func(in[s_func], in[s_args]));
   } catch (Object &e) {
-    out.set("exception", e);
+    out.set(s_exception, e);
   }
   return f_serialize(out);
 }
diff --git a/hphp/runtime/ext/ext_ipc.cpp b/hphp/runtime/ext/ext_ipc.cpp
index f3ba0f037..e045776ad 100644
--- a/hphp/runtime/ext/ext_ipc.cpp
+++ b/hphp/runtime/ext/ext_ipc.cpp
@@ -260,7 +260,7 @@ bool f_msg_receive(CObjRef queue, int64_t desiredmsgtype, VRefParam msgtype,
       return false;
     }
   } else {
-    message = (const char *)MSGBUF_MTEXT(buffer);
+    message = String((const char *)MSGBUF_MTEXT(buffer));
   }
 
   return true;
diff --git a/hphp/runtime/ext/ext_pdo.cpp b/hphp/runtime/ext/ext_pdo.cpp
index 4befecd39..a1c3abec6 100644
--- a/hphp/runtime/ext/ext_pdo.cpp
+++ b/hphp/runtime/ext/ext_pdo.cpp
@@ -1670,7 +1670,7 @@ static inline void fetch_value(sp_PDOStatement stmt, Variant &dest, int colno,
     dest = dest.toString();
   }
   if (dest.isNull() && stmt->dbh->oracle_nulls == PDO_NULL_TO_STRING) {
-    dest = "";
+    dest = empty_string;
   }
 }
 
diff --git a/hphp/runtime/ext/ext_socket.cpp b/hphp/runtime/ext/ext_socket.cpp
index 7e4722235..e32be48e5 100644
--- a/hphp/runtime/ext/ext_socket.cpp
+++ b/hphp/runtime/ext/ext_socket.cpp
@@ -842,6 +842,10 @@ Variant f_socket_recv(CObjRef socket, VRefParam buf, int len, int flags) {
   return retval;
 }
 
+static const StaticString
+  s_2colons("::"),
+  s_0_0_0_0("0.0.0.0");
+
 Variant f_socket_recvfrom(CObjRef socket, VRefParam buf, int len, int flags,
                       VRefParam name, VRefParam port /* = 0 */) {
   if (len <= 0) {
@@ -893,7 +897,7 @@ Variant f_socket_recvfrom(CObjRef socket, VRefParam buf, int len, int flags,
 
       name = String(Util::safe_inet_ntoa(sin.sin_addr));
       if (name.toString().empty()) {
-        name = "0.0.0.0";
+        name = s_0_0_0_0;
       }
       port = ntohs(sin.sin_port);
     }
@@ -922,7 +926,7 @@ Variant f_socket_recvfrom(CObjRef socket, VRefParam buf, int len, int flags,
       if (succ) {
         name = String(addr6, CopyString);
       } else {
-        name = "::";
+        name = s_2colons;
       }
       port = ntohs(sin6.sin6_port);
     }
diff --git a/hphp/test/test_cpp_base.cpp b/hphp/test/test_cpp_base.cpp
index 854e6315d..4c186e830 100644
--- a/hphp/test/test_cpp_base.cpp
+++ b/hphp/test/test_cpp_base.cpp
@@ -337,20 +337,20 @@ bool TestCppBase::TestArray() {
   }
   {
     Array arr;
-    arr.lvalAt(0) = "v1";
-    arr.lvalAt(1) = "v2";
+    arr.lvalAt(0) = String("v1");
+    arr.lvalAt(1) = String("v2");
     VS(arr, CREATE_VECTOR2("v1", "v2"));
   }
   {
     Array arr;
-    arr.lvalAt(s_n1) = "v1";
-    arr.lvalAt(s_n2) = "v2";
+    arr.lvalAt(s_n1) = String("v1");
+    arr.lvalAt(s_n2) = String("v2");
     VS(arr, CREATE_MAP2("n1", "v1", "n2", "v2"));
   }
   {
     Array arr;
     Variant name = "name";
-    arr.lvalAt(name) = "value";
+    arr.lvalAt(name) = String("value");
     VS(arr, CREATE_MAP1("name", "value"));
   }
   {
@@ -400,8 +400,8 @@ bool TestCppBase::TestArray() {
   // membership
   {
     Array arr;
-    arr.lvalAt(0) = "v1";
-    arr.lvalAt(1) = "v2";
+    arr.lvalAt(0) = String("v1");
+    arr.lvalAt(1) = String("v2");
     VERIFY(arr.exists(0));
     arr.remove(0);
     VERIFY(!arr.exists(0));
@@ -412,28 +412,28 @@ bool TestCppBase::TestArray() {
   {
     static const StaticString s_0("0");
     Array arr;
-    arr.lvalAt(0) = "v1";
+    arr.lvalAt(0) = String("v1");
     VERIFY(arr.exists(0));
     arr.remove(String(s_0));
     VERIFY(!arr.exists(0));
   }
   {
     Array arr;
-    arr.lvalAt(0) = "v1";
+    arr.lvalAt(0) = String("v1");
     VERIFY(arr.exists(0));
     arr.remove(Variant("0"));
     VERIFY(!arr.exists(0));
   }
   {
     Array arr;
-    arr.lvalAt(0) = "v1";
+    arr.lvalAt(0) = String("v1");
     VERIFY(arr.exists(0));
     arr.remove(Variant(Variant("0")));
     VERIFY(!arr.exists(0));
   }
   {
     Array arr;
-    arr.lvalAt(0) = "v1";
+    arr.lvalAt(0) = String("v1");
     VERIFY(arr.exists(0));
     arr.remove(Variant(Variant(0.5)));
     VERIFY(!arr.exists(0));
@@ -447,8 +447,8 @@ bool TestCppBase::TestArray() {
   }
   {
     Array arr;
-    arr.lvalAt(s_n1) = "v1";
-    arr.lvalAt(s_n2) = "v2";
+    arr.lvalAt(s_n1) = String("v1");
+    arr.lvalAt(s_n2) = String("v2");
     VERIFY(arr.exists(s_n1));
     arr.remove(s_n1);
     VERIFY(!arr.exists(s_n1));
@@ -458,17 +458,17 @@ bool TestCppBase::TestArray() {
   }
   {
     Array arr;
-    arr.lvalAt() = "test";
+    arr.lvalAt() = String("test");
     VS(arr, CREATE_VECTOR1("test"));
   }
   {
     Array arr;
-    arr.lvalAt(s_name) = "value";
+    arr.lvalAt(s_name) = String("value");
     VERIFY(arr.exists(s_name));
   }
   {
     Array arr;
-    arr.lvalAt(1) = "value";
+    arr.lvalAt(1) = String("value");
     VERIFY(arr.exists(1));
     VERIFY(arr.exists(1.5));
     VERIFY(arr.exists(s_1));
@@ -478,7 +478,7 @@ bool TestCppBase::TestArray() {
   }
   {
     Array arr;
-    arr.lvalAt(s_1) = "value";
+    arr.lvalAt(s_1) = String("value");
     VERIFY(arr.exists(1));
     VERIFY(arr.exists(1.5));
     VERIFY(arr.exists(s_1));
@@ -488,7 +488,7 @@ bool TestCppBase::TestArray() {
   }
   {
     Array arr;
-    arr.lvalAt(1.5) = "value";
+    arr.lvalAt(1.5) = String("value");
     VERIFY(arr.exists(1));
     VERIFY(arr.exists(1.5));
     VERIFY(arr.exists(s_1));
@@ -498,7 +498,7 @@ bool TestCppBase::TestArray() {
   }
   {
     Array arr;
-    arr.lvalAt(Variant(1.5)) = "value";
+    arr.lvalAt(Variant(1.5)) = String("value");
     VERIFY(arr.exists(1));
     VERIFY(arr.exists(1.5));
     VERIFY(arr.exists(s_1));
@@ -508,7 +508,7 @@ bool TestCppBase::TestArray() {
   }
   {
     Array arr;
-    arr.lvalAt(Variant("1")) = "value";
+    arr.lvalAt(Variant("1")) = String("value");
     VERIFY(arr.exists(1));
     VERIFY(arr.exists(1.5));
     VERIFY(arr.exists(s_1));
@@ -657,19 +657,19 @@ bool TestCppBase::TestVariant() {
   }
   {
     Variant v;
-    v.lvalAt(0) = "v0";
-    v.lvalAt(1) = "v1";
+    v.lvalAt(0) = String("v0");
+    v.lvalAt(1) = String("v1");
     VERIFY(v[0] == "v0");
     VERIFY(v[1] == "v1");
   }
   {
     Variant v;
-    v.lvalAt() = "test";
+    v.lvalAt() = String("test");
     VS(v, CREATE_VECTOR1("test"));
   }
   {
     Variant v;
-    v.lvalAt(1) = "test";
+    v.lvalAt(1) = String("test");
     VS(v[1], "test");
     VS(v[1.5], "test");
     VS(v[Variant(1.5)], "test");
@@ -678,7 +678,7 @@ bool TestCppBase::TestVariant() {
   }
   {
     Variant v;
-    v.lvalAt(Variant(1.5)) = "test";
+    v.lvalAt(Variant(1.5)) = String("test");
     VS(v[1], "test");
     VS(v[1.5], "test");
     VS(v[Variant(1.5)], "test");
@@ -687,7 +687,7 @@ bool TestCppBase::TestVariant() {
   }
   {
     Variant v;
-    v.lvalAt(s_1) = "test";
+    v.lvalAt(s_1) = String("test");
     VS(v[1], "test");
     VS(v[1.5], "test");
     VS(v[Variant(1.5)], "test");
@@ -696,7 +696,7 @@ bool TestCppBase::TestVariant() {
   }
   {
     Variant v;
-    v.lvalAt(Variant("1")) = "test";
+    v.lvalAt(Variant("1")) = String("test");
     VS(v[1], "test");
     VS(v[1.5], "test");
     VS(v[Variant(1.5)], "test");
@@ -707,8 +707,8 @@ bool TestCppBase::TestVariant() {
   // membership
   {
     Variant v;
-    v.lvalAt(s_n0) = "v0";
-    v.lvalAt(s_n1) = "v1";
+    v.lvalAt(s_n0) = String("v0");
+    v.lvalAt(s_n1) = String("v1");
     v.remove(s_n1);
     VS(v, CREATE_MAP1(s_n0, "v0"));
     v.append("v2");
@@ -716,29 +716,29 @@ bool TestCppBase::TestVariant() {
   }
   {
     Variant v;
-    v.lvalAt(s_n0) = "v0";
-    v.lvalAt(1) = "v1";
+    v.lvalAt(s_n0) = String("v0");
+    v.lvalAt(1) = String("v1");
     v.remove(Variant(1.5));
     VS(v, CREATE_MAP1("n0", "v0"));
   }
   {
     Variant v;
-    v.lvalAt(s_n0) = "v0";
-    v.lvalAt(1) = "v1";
+    v.lvalAt(s_n0) = String("v0");
+    v.lvalAt(1) = String("v1");
     v.remove(Variant("1"));
     VS(v, CREATE_MAP1("n0", "v0"));
   }
   {
     Variant v;
-    v.lvalAt(s_n0) = "v0";
-    v.lvalAt(1) = "v1";
-    v.remove("1");
+    v.lvalAt(s_n0) = String("v0");
+    v.lvalAt(1) = String("v1");
+    v.remove(String("1"));
     VS(v, CREATE_MAP1("n0", "v0"));
   }
   {
     Variant v;
-    v.lvalAt(s_n0) = "v0";
-    v.lvalAt(empty_string) = "v1";
+    v.lvalAt(s_n0) = String("v0");
+    v.lvalAt(empty_string) = String("v1");
     v.remove(Variant());
     VS(v, CREATE_MAP1("n0", "v0"));
   }
@@ -747,13 +747,13 @@ bool TestCppBase::TestVariant() {
   {
     Variant v1("original");
     Variant v2 = v1;
-    v2 = "changed";
+    v2 = String("changed");
     VERIFY(v1 == "original");
   }
   {
     Variant v1("original");
     Variant v2 = strongBind(v1);
-    v2 = "changed";
+    v2 = String("changed");
     VERIFY(v1 == "changed");
   }
   {
@@ -972,18 +972,18 @@ bool TestCppBase::TestEqualAsStr() {
   var_array[5] = 0.0;
   var_array[6] = 1.0;
   var_array[7] = 42.2;
-  var_array[8] = "0";
-  var_array[9] = "1";
-  var_array[10] = "42";
-  var_array[11] = "x";
+  var_array[8] = String("0");
+  var_array[9] = String("1");
+  var_array[10] = String("42");
+  var_array[11] = String("x");
   var_array[12] = Array::Create();
   Variant v1("original");
   var_array[13] = v1;
   Variant v2("changed");
   var_array[14] = v2;
-  var_array[15] = "";
-  var_array[16] = "Array";
-  var_array[17] = "ARRAY";
+  var_array[15] = empty_string;
+  var_array[16] = String("Array");
+  var_array[17] = String("ARRAY");
   for (int i = 0; i < arr_len; i++) {
     for (int j = 0; j < arr_len; j++) {
       bool eqAsStr = equalAsStr(var_array[i], var_array[j]);
diff --git a/hphp/test/test_ext_apc.cpp b/hphp/test/test_ext_apc.cpp
index 435ee607e..21d41fd6e 100644
--- a/hphp/test/test_ext_apc.cpp
+++ b/hphp/test/test_ext_apc.cpp
@@ -158,7 +158,7 @@ bool TestExtApc::test_apc_fetch() {
   {
     Variant apcdata = f_apc_fetch("apcdata");
     Variant c = apcdata; // bump up ref count to make a MapVariant copy
-    apcdata.set("b", 3); // problem
+    apcdata.set(String("b"), 3); // problem
     VS(apcdata, CREATE_MAP2("a", "test", "b", 3));
   }
   {
diff --git a/hphp/test/test_ext_array.cpp b/hphp/test/test_ext_array.cpp
index ef69bbc98..fbd4c2407 100644
--- a/hphp/test/test_ext_array.cpp
+++ b/hphp/test/test_ext_array.cpp
@@ -1115,7 +1115,7 @@ bool TestExtArray::test_array_unshift() {
      ")\n");
 
   q = CREATE_MAP3(0, "orange", 1, "banana", "a", "dummy");
-  q.remove("a");
+  q.remove(String("a"));
   f_array_unshift(3, ref(q), "apple", CREATE_VECTOR1("raspberry"));
   VS(f_print_r(q, true),
      "Array\n"
diff --git a/hphp/test/test_ext_sqlite3.cpp b/hphp/test/test_ext_sqlite3.cpp
index 66e48836c..b94511188 100644
--- a/hphp/test/test_ext_sqlite3.cpp
+++ b/hphp/test/test_ext_sqlite3.cpp
@@ -80,7 +80,7 @@ bool TestExtSqlite3::test_sqlite3() {
 
     Variant id = "DEF";
     VERIFY(stmt->t_bindvalue(":id", id, SQLITE3_TEXT));
-    id = "ABC";
+    id = String("ABC");
     {
       Object objResult = stmt->t_execute();
       c_SQLite3Result *res = objResult.getTyped<c_SQLite3Result>();
@@ -89,9 +89,9 @@ bool TestExtSqlite3::test_sqlite3() {
 
     VERIFY(stmt->t_clear());
     VERIFY(stmt->t_reset());
-    id = "DEF";
+    id = String("DEF");
     VERIFY(stmt->t_bindparam(":id", ref(id), SQLITE3_TEXT));
-    id = "ABC";
+    id = String("ABC");
     {
       Object objResult = stmt->t_execute();
       c_SQLite3Result *res = objResult.getTyped<c_SQLite3Result>();
diff --git a/hphp/test/test_ext_xml.cpp b/hphp/test/test_ext_xml.cpp
index bc9221857..53a46f40b 100644
--- a/hphp/test/test_ext_xml.cpp
+++ b/hphp/test/test_ext_xml.cpp
@@ -74,9 +74,9 @@ bool TestExtXml::test_xml_parse_into_struct() {
   Variant vals, index;
   f_xml_parse_into_struct(p, simple, ref(vals), ref(index));
   f_xml_parser_free(p);
-  VS(f_print_r(index.rvalAt("PARA"),1),
+  VS(f_print_r(index.rvalAt(String("PARA")),1),
     "Array\n(\n    [0] => 0\n    [1] => 2\n)\n");
-  VS(f_print_r(index.rvalAt("NOTE"),1),
+  VS(f_print_r(index.rvalAt(String("NOTE")),1),
     "Array\n(\n    [0] => 1\n)\n");
   VS(f_print_r(vals.rvalAt(0),1),
     "Array\n(\n    [tag] => PARA\n    [type] => open\n    [level] => 1\n)\n");