diff --git a/Makefile.rules b/Makefile.rules
index 78988995347..4b759e6b490 100644
--- a/Makefile.rules
+++ b/Makefile.rules
@@ -221,7 +221,7 @@ else
   endif
 endif
 
-CXX.Flags += $(CXXFLAGS) -Wformat
+CXX.Flags += $(CXXFLAGS)
 C.Flags   += $(CFLAGS)
 CPP.Flags += $(CPPFLAGS)
 LD.Flags  += $(LDFLAGS)