diff --git a/dist/post_run/index.js b/dist/post_run/index.js
index 4005a23..d463277 100644
--- a/dist/post_run/index.js
+++ b/dist/post_run/index.js
@@ -54566,7 +54566,7 @@ function expand(str, isTop) {
   var isOptions = m.body.indexOf(',') >= 0;
   if (!isSequence && !isOptions) {
     // {a},b}
-    if (m.post.match(/,.*\}/)) {
+    if (m.post.match(/,(?!,).*\}/)) {
       str = m.pre + '{' + m.body + escClose + m.post;
       return expand(str);
     }
diff --git a/dist/run/index.js b/dist/run/index.js
index f3eef28..4603bb4 100644
--- a/dist/run/index.js
+++ b/dist/run/index.js
@@ -54566,7 +54566,7 @@ function expand(str, isTop) {
   var isOptions = m.body.indexOf(',') >= 0;
   if (!isSequence && !isOptions) {
     // {a},b}
-    if (m.post.match(/,.*\}/)) {
+    if (m.post.match(/,(?!,).*\}/)) {
       str = m.pre + '{' + m.body + escClose + m.post;
       return expand(str);
     }