diff --git a/src/util.js b/src/util.js
index 55674d7..f0ad971 100644
--- a/src/util.js
+++ b/src/util.js
@@ -1515,7 +1515,7 @@ const patchTokens = function (tokens) {
     // patch for "っ" at the tail of 動詞、形容詞
     for (let j = 0; j < tokens.length; j++) {
         if (tokens[j].pos && (tokens[j].pos === "動詞" || tokens[j].pos === "形容詞") && tokens[j].surface_form.length > 1 && (tokens[j].surface_form[tokens[j].surface_form.length - 1] === "っ" || tokens[j].surface_form[tokens[j].surface_form.length - 1] === "ッ")) {
-            if (j + 1 < tokens.length && tokens[j + 1].pos && (tokens[j + 1].pos === "動詞" || tokens[j + 1].pos === "助動詞")) {
+            if (j + 1 < tokens.length) {
                 tokens[j].surface_form += tokens[j + 1].surface_form;
                 if (tokens[j].pronunciation) {
                     tokens[j].pronunciation += tokens[j + 1].pronunciation;