diff --git a/src/neo/SmartContract/ApplicationEngine.Contract.cs b/src/neo/SmartContract/ApplicationEngine.Contract.cs
index c537469da6..5b84938289 100644
--- a/src/neo/SmartContract/ApplicationEngine.Contract.cs
+++ b/src/neo/SmartContract/ApplicationEngine.Contract.cs
@@ -1,6 +1,7 @@
 using Neo.Cryptography.ECC;
 using Neo.IO;
 using Neo.Ledger;
+using Neo.Network.P2P.Payloads;
 using Neo.SmartContract.Manifest;
 using Neo.SmartContract.Native;
 using Neo.VM;
@@ -164,7 +165,27 @@ private void CallContractInternal(UInt160 contractHash, string method, Array arg
         internal bool IsStandardContract(UInt160 hash)
         {
             ContractState contract = Snapshot.Contracts.TryGet(hash);
-            return contract is null || contract.Script.IsStandardContract();
+
+            // It's a stored contract
+
+            if (contract != null) return contract.Script.IsStandardContract();
+
+            // Try to find it in the transaction
+
+            if (ScriptContainer is Transaction tx)
+            {
+                foreach (var witness in tx.Witnesses)
+                {
+                    if (witness.ScriptHash == hash)
+                    {
+                        return witness.VerificationScript.IsStandardContract();
+                    }
+                }
+            }
+
+            // It's not possible to determine if it's standard
+
+            return false;
         }
 
         internal CallFlags GetCallFlags()
diff --git a/tests/neo.UnitTests/SmartContract/UT_InteropService.NEO.cs b/tests/neo.UnitTests/SmartContract/UT_InteropService.NEO.cs
index 283fdc1d3f..5d78c4ebd5 100644
--- a/tests/neo.UnitTests/SmartContract/UT_InteropService.NEO.cs
+++ b/tests/neo.UnitTests/SmartContract/UT_InteropService.NEO.cs
@@ -110,7 +110,7 @@ public void TestAccount_IsStandard()
                                     0x01, 0x01, 0x01, 0x01, 0x01,
                                     0x01, 0x01, 0x01, 0x01, 0x01,
                                     0x01, 0x01, 0x01, 0x01, 0x01 };
-            engine.IsStandardContract(new UInt160(hash)).Should().BeTrue();
+            engine.IsStandardContract(new UInt160(hash)).Should().BeFalse();
 
             var snapshot = Blockchain.Singleton.GetSnapshot();
             var state = TestUtils.GetContract();
@@ -118,6 +118,11 @@ public void TestAccount_IsStandard()
             engine = new ApplicationEngine(TriggerType.Application, null, snapshot, 0, true);
             engine.LoadScript(new byte[] { 0x01 });
             engine.IsStandardContract(state.ScriptHash).Should().BeFalse();
+
+            state.Script = Contract.CreateSignatureRedeemScript(Blockchain.StandbyValidators[0]);
+            engine = new ApplicationEngine(TriggerType.Application, null, snapshot, 0, true);
+            engine.LoadScript(new byte[] { 0x01 });
+            engine.IsStandardContract(state.ScriptHash).Should().BeTrue();
         }
 
         [TestMethod]