diff --git a/config.w32 b/config.w32
index 9c2373c..d8f1746 100644
--- a/config.w32
+++ b/config.w32
@@ -7,6 +7,7 @@ if (PHP_FANN == "yes") {
 	if (CHECK_LIB("libfann.lib;doublefann.lib;fanndouble.lib", "fann", PHP_FANN) &&
 			CHECK_HEADER_ADD_INCLUDE("fann.h", "CFLAGS_FANN")) {
 
+		AC_DEFINE("HAVE_FANN_2_2", 1);
 		AC_DEFINE("PHP_FANN_DOUBLE", 1);
 
 		EXTENSION("fann", "fann.c fann_connection.c");