--- builds/posix/make.rules.orig	2016-06-30 09:34:53 UTC
+++ builds/posix/make.rules
@@ -37,6 +37,8 @@ WFLAGS:=$(CPPFLAGS) -I$(SRC_ROOT)/includ
 
 ifeq ($(STD_ICU),false)
   WFLAGS:= $(WFLAGS) -I$(ROOT)/extern/icu/source/common -I$(ROOT)/extern/icu/source/i18n
+else
+  WFLAGS:= $(WFLAGS) $(shell icu-config --cppflags)
 endif
 
 ifeq ($(IsProdTypeBuild),Y)