diff --git a/src/Makefile b/src/Makefile
index c0aa26737..9db3e6934 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -47,7 +47,7 @@ endif
 
 USEASM?=true
 
-ifneq ($(SANITIZE),)
+ifneq ($(strip $(SANITIZE)),)
 	CFLAGS+= -fsanitize=$(SANITIZE) -DSANITIZE
 	CXXFLAGS+= -fsanitize=$(SANITIZE) -DSANITIZE
 	LDFLAGS+= -fsanitize=$(SANITIZE)