diff --git a/scripts/kconfig/lex.zconf.c_shipped b/scripts/kconfig/lex.zconf.c_shipped
index 800f8c71c407f32893020c72c14d043147e8eeb1..0fdc9049296f5985d9abaf46aeda7e607ef5a80f 100644
--- a/scripts/kconfig/lex.zconf.c_shipped
+++ b/scripts/kconfig/lex.zconf.c_shipped
@@ -2264,7 +2264,7 @@ FILE *zconf_fopen(const char *name)
 	FILE *f;
 
 	f = fopen(name, "r");
-	if (!f && name[0] != '/') {
+	if (!f && name != NULL && name[0] != '/') {
 		env = getenv(SRCTREE);
 		if (env) {
 			sprintf(fullname, "%s/%s", env, name);
diff --git a/scripts/kconfig/zconf.l b/scripts/kconfig/zconf.l
index cfa46077c6b43a45dad6d89c60ea5dd274c566cf..187d38ccadd57f489b89cbbf16798cdf5f08ef49 100644
--- a/scripts/kconfig/zconf.l
+++ b/scripts/kconfig/zconf.l
@@ -265,7 +265,7 @@ FILE *zconf_fopen(const char *name)
 	FILE *f;
 
 	f = fopen(name, "r");
-	if (!f && name[0] != '/') {
+	if (!f && name != NULL && name[0] != '/') {
 		env = getenv(SRCTREE);
 		if (env) {
 			sprintf(fullname, "%s/%s", env, name);