diff --git a/Makefile b/Makefile
index 37a1f3039623..b6ee29cdae95 100644
--- a/Makefile
+++ b/Makefile
@@ -744,6 +744,8 @@ KBUILD_CFLAGS += -Wno-tautological-compare
 # source of a reference will be _MergedGlobals and not on of the whitelisted names.
 # See modpost pattern 2
 KBUILD_CFLAGS += -mno-global-merge
+KBUILD_CFLAGS += $(call cc-disable-warning, undefined-optimized)
+KBUILD_CFLAGS += -fno-builtin
 else
 
 # These warnings generated too much noise in a regular build.