diff --git a/web3.js/src/connection.js b/web3.js/src/connection.js
index 10907472f1..f3efb1ed27 100644
--- a/web3.js/src/connection.js
+++ b/web3.js/src/connection.js
@@ -575,7 +575,7 @@ const GetBlockTimeRpcResult = struct({
   jsonrpc: struct.literal('2.0'),
   id: 'string',
   error: 'any?',
-  result: struct.union(['null', 'number']),
+  result: struct.union(['null', 'number', 'undefined']),
 });
 
 /**