--- a/js/src/frontend/BinSource.cpp
+++ b/js/src/frontend/BinSource.cpp
@@ -2622,16 +2622,31 @@ ASTReader::parseKeyValueList(SimpleToken
 }
 
 bool
 ASTReader::readString(SimpleTokenReader* reader, MutableHandleString out) {
     if (out) {
         return this->raiseError();
     }
 
+    RootedAtom atom(this->cx);
+    if (!this->readString(reader, &atom)) {
+        return false;
+    }
+
+    out.set(atom);
+    return true;
+}
+
+bool
+ASTReader::readString(SimpleTokenReader* reader, MutableHandleAtom out) {
+    if (out) {
+        return this->raiseError();
+    }
+
     Maybe<std::string> string;
     if (!this->readString(reader, string)) {
         return false;
     }
 
     if (!string) {
         return true;
     }