--- a/js/src/jsreflect.cpp
+++ b/js/src/jsreflect.cpp
@@ -2314,19 +2314,17 @@ ASTSerializer::statement(JSParseNode *pn
         LOCAL_NOT_REACHED("unexpected statement type");
     }
 }
 
 bool
 ASTSerializer::leftAssociate(JSParseNode *pn, Value *dst)
 {
     JS_ASSERT(pn->pn_arity == PN_LIST);
-
-    const size_t len = pn->pn_count;
-    JS_ASSERT(len >= 1);
+    JS_ASSERT(pn->pn_count >= 1);
 
     TokenKind tk = PN_TYPE(pn);
     bool lor = tk == TOK_OR;
     bool logop = lor || (tk == TOK_AND);
 
     JSParseNode *head = pn->pn_head;
     Value left;
     if (!expression(head, &left))