diff --git a/README.md b/README.md
index 70e4a7d..d67554a 100644
--- a/README.md
+++ b/README.md
@@ -175,7 +175,7 @@ $contract->at($contractAddress)->send($functionName, $params, $callback);
 $contract->bytecode($bytecode)->estimateGas($params, $callback);
 
 // estimate function gas
-$contract->bytecode($bytecode)->estimateGas($functionName, $params, $callback);
+$contract->at($contractAddress)->estimateGas($functionName, $params, $callback);
 ```
 
 # Examples