diff --git a/lib/parse.js b/lib/parse.js
index 3e511e185..6e5aac33f 100644
--- a/lib/parse.js
+++ b/lib/parse.js
@@ -2548,6 +2548,7 @@ function parse($TEXT, options) {
 
         expect("{");
         // mark in class feild,
+        const save_in_class = S.in_class;
         S.in_class = true;
         while (is("punc", ";")) { next(); }  // Leading semicolons are okay in class bodies.
         while (!is("punc", "}")) {
@@ -2558,7 +2559,7 @@ function parse($TEXT, options) {
             while (is("punc", ";")) { next(); }
         }
         // mark in class feild,
-        S.in_class = false;
+        S.in_class = save_in_class;
 
         S.input.pop_directives_stack();