diff --git a/hphp/runtime/vm/bytecode.cpp b/hphp/runtime/vm/bytecode.cpp
index 0cf17fc88..796b27986 100644
--- a/hphp/runtime/vm/bytecode.cpp
+++ b/hphp/runtime/vm/bytecode.cpp
@@ -1508,15 +1508,10 @@ void VMExecutionContext::syncGdbState() {
   }
 }
 
-static bool jitIsEnabled(const Unit* unit) {
-  if (!ThreadInfo::s_threadInfo->m_reqInjectionData.getJit()) return false;
-  return unit == nullptr || !unit->isInterpretOnly();
-}
-
 void VMExecutionContext::enterVMPrologue(ActRec* enterFnAr) {
   assert(enterFnAr);
   Stats::inc(Stats::VMEnter);
-  if (jitIsEnabled(enterFnAr->m_func->unit())) {
+  if (ThreadInfo::s_threadInfo->m_reqInjectionData.getJit()) {
     int np = enterFnAr->m_func->numParams();
     int na = enterFnAr->numArgs();
     if (na > np) na = np + 1;
@@ -1537,7 +1532,7 @@ void VMExecutionContext::enterVMWork(ActRec* enterFnAr) {
     start = enterFnAr->m_func->getFuncBody();
   }
   Stats::inc(Stats::VMEnter);
-  if (jitIsEnabled(m_fp->unit())) {
+  if (ThreadInfo::s_threadInfo->m_reqInjectionData.getJit()) {
     (void) m_fp->unit()->offsetOf(m_pc); /* assert */
     if (enterFnAr) {
       assert(start);
diff --git a/hphp/runtime/vm/jit/translator.cpp b/hphp/runtime/vm/jit/translator.cpp
index b32637e29..b94d392f1 100755
--- a/hphp/runtime/vm/jit/translator.cpp
+++ b/hphp/runtime/vm/jit/translator.cpp
@@ -3442,6 +3442,7 @@ Translator::Get() {
 bool
 Translator::isSrcKeyInBL(const SrcKey& sk) {
   auto unit = sk.unit();
+  if (unit->isInterpretOnly()) return true;
   Lock l(m_dbgBlacklistLock);
   if (m_dbgBLSrcKey.find(sk) != m_dbgBLSrcKey.end()) {
     return true;
diff --git a/hphp/runtime/vm/unit.h b/hphp/runtime/vm/unit.h
index 3aa9a40a4..79baf7c24 100644
--- a/hphp/runtime/vm/unit.h
+++ b/hphp/runtime/vm/unit.h
@@ -644,7 +644,7 @@ public:
     m_cacheMask = 1 << (id & 7);
   }
   bool isInterpretOnly() const { return m_interpretOnly; }
-  void setInterpretOnly() { m_interpretOnly = false; }
+  void setInterpretOnly() { m_interpretOnly = true; }
   bool isMergeOnly() const { return m_mergeOnly; }
   void clearMergeOnly() { m_mergeOnly = false; }
   bool isEmpty() const { return m_mergeState & UnitMergeStateEmpty; }