diff --git a/src/systemd/sd-json.h b/src/systemd/sd-json.h
index c28e5dd0e76..359149ef9e0 100644
--- a/src/systemd/sd-json.h
+++ b/src/systemd/sd-json.h
@@ -335,7 +335,7 @@ int sd_json_variant_strv(sd_json_variant *v, char ***ret);
 int sd_json_variant_unbase64(sd_json_variant *v, void **ret, size_t *ret_size);
 int sd_json_variant_unhex(sd_json_variant *v, void **ret, size_t *ret_size);
 
-const char* sd_json_variant_type_to_string(sd_json_variant_type_t t);
+const char* sd_json_variant_type_to_string(sd_json_variant_type_t i);
 sd_json_variant_type_t sd_json_variant_type_from_string(const char *s);
 
 static __inline__ int sd_json_format_enabled(sd_json_format_flags_t flags) {