diff --git a/spa/include/spa/utils/json.h b/spa/include/spa/utils/json.h
index 99f32d4d4..e6f599d84 100644
--- a/spa/include/spa/utils/json.h
+++ b/spa/include/spa/utils/json.h
@@ -112,7 +112,7 @@ static inline int spa_json_next(struct spa_json * iter, const char **value)
 				iter->state = __STRUCT;
 				if (iter->depth > 0)
 					goto again;
-				return iter->cur++ - *value;
+				return iter->cur - *value;
 			}
 			continue;
 		case __STRING: