diff --git a/lib/Makefile b/lib/Makefile
index 3b17690456514aac560465ec331aaed5b3dca977..30337431d10e3fbdb312080d86482ba35595cfe5 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -426,3 +426,7 @@ $(obj)/$(TEST_FORTIFY_LOG): $(addprefix $(obj)/, $(TEST_FORTIFY_LOGS)) FORCE
 ifeq ($(CONFIG_FORTIFY_SOURCE),y)
 $(obj)/string.o: $(obj)/$(TEST_FORTIFY_LOG)
 endif
+
+# Some architectures define __NO_FORTIFY if __SANITIZE_ADDRESS__ is undefined.
+# Pass CFLAGS_KASAN to avoid warnings.
+$(foreach x, $(patsubst %.log,%.o,$(TEST_FORTIFY_LOGS)), $(eval KASAN_SANITIZE_$(x) := y))