diff --git a/src/Paymaster.sol b/src/Paymaster.sol
index 360a8c5..618b7a9 100644
--- a/src/Paymaster.sol
+++ b/src/Paymaster.sol
@@ -25,6 +25,8 @@ contract Paymaster is BasePaymaster {
     uint256 private constant SIGNATURE_OFFSET = VALID_TIMESTAMP_OFFSET + 64;
 
     constructor(IEntryPoint _entryPoint, address _verifyingSigner) BasePaymaster(_entryPoint) {
+        require(_verifyingSigner != address(0), "Paymaster: verifyingSigner cannot be address(0)");
+        require(_verifyingSigner != msg.sender, "Paymaster: verifyingSigner cannot be the owner");
         verifyingSigner = _verifyingSigner;
     }
 
diff --git a/test/Paymaster.t.sol b/test/Paymaster.t.sol
index 8fd4825..670dedc 100644
--- a/test/Paymaster.t.sol
+++ b/test/Paymaster.t.sol
@@ -31,6 +31,16 @@ contract PaymasterTest is Test {
         account = factory.createAccount(ACCOUNT_OWNER, 0);
     }
 
+    function test_zeroAddressVerifyingSigner() public {
+        vm.expectRevert("Paymaster: verifyingSigner cannot be address(0)");
+        new Paymaster(entrypoint, address(0));
+    }
+
+    function test_ownerVerifyingSigner() public {
+        vm.expectRevert("Paymaster: verifyingSigner cannot be the owner");
+        new Paymaster(entrypoint, address(this));
+    }
+
     function test_parsePaymasterAndData() public {
         bytes memory paymasterAndData = abi.encodePacked(address(paymaster), abi.encode(MOCK_VALID_UNTIL, MOCK_VALID_AFTER), MOCK_SIG);
         (uint48 validUntil, uint48 validAfter, bytes memory signature) = paymaster.parsePaymasterAndData(paymasterAndData);