diff --git a/Makefile.in b/Makefile.in
index c32cc705..112c3ba2 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -42,7 +42,7 @@ CFLAGS = @CFLAGS@ \
 	 -DBTRFS_FLAT_INCLUDES \
 	 -D_XOPEN_SOURCE=700  \
 	 -fno-strict-aliasing \
-	 -fPIC $(KBUILD_CFLAGS) $(EXTRA_CFLAGS)
+	 -fPIC $(EXTRAWARN_CFLAGS) $(EXTRA_CFLAGS)
 
 LDFLAGS = @LDFLAGS@ \
 	  -rdynamic $(EXTRA_LDFLAGS)