diff --git a/mozglue/build/Makefile.in b/mozglue/build/Makefile.in
index 1cfa41ea04..2e484a92a9 100644
--- a/mozglue/build/Makefile.in
+++ b/mozglue/build/Makefile.in
@@ -8,7 +8,7 @@ include $(topsrcdir)/config/config.mk
 
 ifeq (WINNT,$(OS_TARGET))
 mozglue.def: mozglue.def.in $(GLOBAL_DEPS)
-	$(call py_action,preprocessor,$(if $(MOZ_REPLACE_MALLOC),-DMOZ_REPLACE_MALLOC) $(ACDEFINES) $< -o $@)
+	$(call py_action,preprocessor,$(if $(MOZ_REPLACE_MALLOC),-DMOZ_REPLACE_MALLOC) $(if $(GNU_CC),-DGNU_CC) $(ACDEFINES) $< -o $@)
 
 GARBAGE += mozglue.def
 endif
diff --git a/mozglue/build/mozglue.def.in b/mozglue/build/mozglue.def.in
index 25ef309d2e..4a07d9d0b4 100644
--- a/mozglue/build/mozglue.def.in
+++ b/mozglue/build/mozglue.def.in
@@ -34,7 +34,7 @@ EXPORTS
   _wcsdup=wrap_wcsdup
   jemalloc_stats
   jemalloc_free_dirty_pages
-#if defined(__GNUC__)
+#ifdef GNU_CC
   _Z14mozalloc_abortPKc
 #else
   ?mozalloc_abort@@YAXQEBD@Z