diff --git a/src/account/ModularAccountBase.sol b/src/account/ModularAccountBase.sol
index a362705d..d5adcf21 100644
--- a/src/account/ModularAccountBase.sol
+++ b/src/account/ModularAccountBase.sol
@@ -371,6 +371,7 @@ abstract contract ModularAccountBase is
     function upgradeToAndCall(address newImplementation, bytes calldata data)
         public
         payable
+        virtual
         override
         onlyProxy
         wrapNativeFunction
diff --git a/src/account/SemiModularAccount7702.sol b/src/account/SemiModularAccount7702.sol
index 950607fc..70d09419 100644
--- a/src/account/SemiModularAccount7702.sol
+++ b/src/account/SemiModularAccount7702.sol
@@ -12,6 +12,8 @@ import {SemiModularAccountBase} from "./SemiModularAccountBase.sol";
 /// @dev Inherits SemiModularAccountBase. This account can be used as the delegate contract of an EOA with
 /// EIP-7702, where address(this) (aka the EOA address) is the default fallback signer.
 contract SemiModularAccount7702 is SemiModularAccountBase {
+    error UpgradeNotAllowed();
+
     constructor(IEntryPoint anEntryPoint) SemiModularAccountBase(anEntryPoint) {}
 
     /// @inheritdoc IModularAccount
@@ -34,4 +36,8 @@ contract SemiModularAccount7702 is SemiModularAccountBase {
 
         return address(this);
     }
+
+    function upgradeToAndCall(address, bytes calldata) public payable override {
+        revert UpgradeNotAllowed();
+    }
 }