diff --git a/src/proxy.sol b/src/proxy.sol
index 4f475bc..1cc8768 100644
--- a/src/proxy.sol
+++ b/src/proxy.sol
@@ -58,6 +58,11 @@ contract DSProxy is DSAuth, DSNote {
         returns (bytes memory response)
     {
         require(_target != address(0), "ds-proxy-target-address-required");
+        uint csize;
+        assembly {
+            csize := extcodesize(_target)
+        }
+        require(csize > 0, "ds-proxy-target-invalid-address");
 
         // call contract in current context
         assembly {
diff --git a/src/proxy.t.sol b/src/proxy.t.sol
index ddf6cbf..a359514 100644
--- a/src/proxy.t.sol
+++ b/src/proxy.t.sol
@@ -319,6 +319,19 @@ contract DSProxyTest is DSTest {
         assertEq(address(this).balance, myBalance + 5);
     }
 
+    ///test 14 - check failure when an address without code is used as target
+    function testFail_executeNonContract() public {
+        bytes memory data = abi.encodeWithSignature("test()");
+        proxy.execute(address(0x1), data);
+    }
+
+    ///test 15 - check failure when a non existing function is called
+    function testFail_executeNonFunction() public {
+        address testContract = address(new TestContract());
+        bytes memory data = abi.encodeWithSignature("nonExistingFunction()");
+        proxy.execute(testContract, data);
+    }
+
     function() external payable {
     }
 }