diff --git a/tools/testing/selftests/gpio/gpio-mockup-cdev.c b/tools/testing/selftests/gpio/gpio-mockup-cdev.c
index e83eac71621a0e2d7913f056b7a8d35c41912e8e..d1640f44f8ac2a6fda7a5f75605f83fcaa165dc0 100644
--- a/tools/testing/selftests/gpio/gpio-mockup-cdev.c
+++ b/tools/testing/selftests/gpio/gpio-mockup-cdev.c
@@ -117,7 +117,7 @@ int main(int argc, char *argv[])
 {
 	char *chip;
 	int opt, ret, cfd, lfd;
-	unsigned int offset, val, abiv;
+	unsigned int offset, val = 0, abiv;
 	uint32_t flags_v1;
 	uint64_t flags_v2;