--- mozilla/config/config.mk.fix	2016-06-20 15:03:19.000000000 +0300
+++ mozilla/config/config.mk	2016-06-20 15:03:24.000000000 +0300
@@ -345,8 +345,10 @@ endif # WINNT && (MOS_PROFILE_GENERATE ^
 ifdef CLANG_CL
 ALLOW_COMPILER_WARNINGS=1
 endif # CLANG_CL
 
+ALLOW_COMPILER_WARNINGS=1
+
 # Use warnings-as-errors if ALLOW_COMPILER_WARNINGS is not set to 1 (which
 # includes the case where it's undefined).
 ifneq (1,$(ALLOW_COMPILER_WARNINGS))
 CXXFLAGS += $(WARNINGS_AS_ERRORS)