diff --git a/src/parseTools.js b/src/parseTools.js
index eacd9cc50cc62..8b125b998f20e 100644
--- a/src/parseTools.js
+++ b/src/parseTools.js
@@ -904,14 +904,14 @@ function defineI64Param(name) {
 
 
 function receiveI64ParamAsI53(name, onError, handleErrors = true) {
-  var errorHandler = handleErrors ? `if (isNaN(${name})) return ${onError}` : '';
+  var errorHandler = handleErrors ? `if (isNaN(${name})) { return ${onError}; }` : '';
   if (WASM_BIGINT) {
     // Just convert the bigint into a double.
-    return `${name} = bigintToI53Checked(${name});${errorHandler};`;
+    return `${name} = bigintToI53Checked(${name});${errorHandler}`;
   }
   // Convert the high/low pair to a Number, checking for
   // overflow of the I53 range and returning onError in that case.
-  return `var ${name} = convertI32PairToI53Checked(${name}_low, ${name}_high);${errorHandler};`;
+  return `var ${name} = convertI32PairToI53Checked(${name}_low, ${name}_high);${errorHandler}`;
 }
 
 function receiveI64ParamAsI53Unchecked(name) {