diff --git a/js/src/frontend/Parser.cpp b/js/src/frontend/Parser.cpp
index 22edacc244e1..e0606b1a7df1 100644
--- a/js/src/frontend/Parser.cpp
+++ b/js/src/frontend/Parser.cpp
@@ -2912,6 +2912,10 @@ FunctionNode* Parser<FullParseHandler, Unit>::standaloneLazyFunction(
   return funNode;
 }
 
+void ParserBase::setFunctionEndFromCurrentToken(FunctionBox* funbox) const {
+  funbox->setEnd(anyChars.currentToken().pos.end);
+}
+
 template <class ParseHandler, typename Unit>
 bool GeneralParser<ParseHandler, Unit>::functionFormalParametersAndBody(
     InHandling inHandling, YieldHandling yieldHandling,
@@ -3052,7 +3056,7 @@ bool GeneralParser<ParseHandler, Unit>::functionFormalParametersAndBody(
       return false;
     }
 
-    funbox->setEnd(anyChars);
+    setFunctionEndFromCurrentToken(funbox);
   } else {
     MOZ_ASSERT(kind == FunctionSyntaxKind::Arrow);
 
@@ -3060,7 +3064,7 @@ bool GeneralParser<ParseHandler, Unit>::functionFormalParametersAndBody(
       return false;
     }
 
-    funbox->setEnd(anyChars);
+    setFunctionEndFromCurrentToken(funbox);
 
     if (kind == FunctionSyntaxKind::Statement) {
       if (!matchOrInsertSemicolon()) {
@@ -7161,7 +7165,7 @@ GeneralParser<ParseHandler, Unit>::synthesizeConstructor(
   }
   funbox->initWithEnclosingParseContext(pc_, functionSyntaxKind);
   handler_.setFunctionBox(funNode, funbox);
-  funbox->setEnd(anyChars);
+  setFunctionEndFromCurrentToken(funbox);
 
   // Push a SourceParseContext on to the stack.
   SourceParseContext funpc(this, funbox, /* newDirectives = */ nullptr);
@@ -7352,7 +7356,7 @@ GeneralParser<ParseHandler, Unit>::fieldInitializerOpt(
 
   // Update the end position of the parse node.
   handler_.setEndPosition(funNode, wholeInitializerPos.end);
-  funbox->setEnd(anyChars);
+  setFunctionEndFromCurrentToken(funbox);
 
   // Create a ListNode for the parameters + body (there are no parameters).
   ListNodeType argsbody =
diff --git a/js/src/frontend/Parser.h b/js/src/frontend/Parser.h
index d6a6105e7447..21fed2a5e0a9 100644
--- a/js/src/frontend/Parser.h
+++ b/js/src/frontend/Parser.h
@@ -457,6 +457,8 @@ class MOZ_STACK_CLASS ParserBase : public ParserSharedBase,
   JSAtom* prefixAccessorName(PropertyType propType, HandleAtom propAtom);
 
   MOZ_MUST_USE bool setSourceMapInfo();
+
+  void setFunctionEndFromCurrentToken(FunctionBox* funbox) const;
 };
 
 enum FunctionCallBehavior {
@@ -824,6 +826,7 @@ class MOZ_STACK_CLASS GeneralParser : public PerHandlerParser<ParseHandler> {
   using Base::prefixAccessorName;
   using Base::processExport;
   using Base::processExportFrom;
+  using Base::setFunctionEndFromCurrentToken;
 
  private:
   inline FinalParser* asFinalParser();
diff --git a/js/src/frontend/SharedContext.h b/js/src/frontend/SharedContext.h
index 55ca96924fee..c08b4cd9e353 100644
--- a/js/src/frontend/SharedContext.h
+++ b/js/src/frontend/SharedContext.h
@@ -555,13 +555,11 @@ class FunctionBox : public ObjectBox, public SharedContext {
     startColumn = column;
   }
 
-  void setEnd(const TokenStreamAnyChars& anyChars) {
+  void setEnd(uint32_t end) {
     // For all functions except class constructors, the buffer and
     // toString ending positions are the same. Class constructors override
     // the toString ending position with the end of the class definition.
-    uint32_t offset = anyChars.currentToken().pos.end;
-    bufEnd = offset;
-    toStringEnd = offset;
+    bufEnd = toStringEnd = end;
   }
 
   void trace(JSTracer* trc) override;