diff --git a/jsmn.c b/jsmn.c
index e38a472..cc300e3 100644
--- a/jsmn.c
+++ b/jsmn.c
@@ -161,6 +161,8 @@ jsmnerr_t jsmn_parse(jsmn_parser *parser, const char *js, jsmntok_t *tokens,
 						break;
 					}
 				}
+				/* Error if unmatched closing bracket */
+				if (i == -1) return JSMN_ERROR_INVAL;
 				for (; i >= 0; i--) {
 					token = &tokens[i];
 					if (token->start != -1 && token->end == -1) {