diff --git a/examples/call/contracts/Universal.sol b/examples/call/contracts/Universal.sol
index df36279..ca8f840 100644
--- a/examples/call/contracts/Universal.sol
+++ b/examples/call/contracts/Universal.sol
@@ -34,8 +34,9 @@ contract Universal is UniversalContract {
         (, uint256 gasFee) = IZRC20(zrc20).withdrawGasFeeWithGasLimit(
             callOptions.gasLimit
         );
-        if (!IZRC20(zrc20).transferFrom(msg.sender, address(this), gasFee))
+        if (!IZRC20(zrc20).transferFrom(msg.sender, address(this), gasFee)) {
             revert TransferFailed();
+        }
         IZRC20(zrc20).approve(address(gateway), gasFee);
         gateway.call(receiver, zrc20, message, callOptions, revertOptions);
     }
@@ -48,8 +49,9 @@ contract Universal is UniversalContract {
     ) external {
         (address gasZRC20, uint256 gasFee) = IZRC20(zrc20).withdrawGasFee();
         uint256 target = zrc20 == gasZRC20 ? amount + gasFee : amount;
-        if (!IZRC20(zrc20).transferFrom(msg.sender, address(this), target))
+        if (!IZRC20(zrc20).transferFrom(msg.sender, address(this), target)) {
             revert TransferFailed();
+        }
         IZRC20(zrc20).approve(address(gateway), target);
         if (zrc20 != gasZRC20) {
             if (
@@ -58,7 +60,9 @@ contract Universal is UniversalContract {
                     address(this),
                     gasFee
                 )
-            ) revert TransferFailed();
+            ) {
+                revert TransferFailed();
+            }
             IZRC20(gasZRC20).approve(address(gateway), gasFee);
         }
         gateway.withdraw(receiver, amount, zrc20, revertOptions);
@@ -85,7 +89,9 @@ contract Universal is UniversalContract {
                     address(this),
                     gasFee
                 )
-            ) revert TransferFailed();
+            ) {
+                revert TransferFailed();
+            }
             IZRC20(gasZRC20).approve(address(gateway), gasFee);
         }
         gateway.withdrawAndCall(