diff --git a/blockchain/validate.go b/blockchain/validate.go
index 0ad131599..7c25ff9e2 100644
--- a/blockchain/validate.go
+++ b/blockchain/validate.go
@@ -1196,6 +1196,8 @@ func (b *BlockChain) checkConnectBlock(node *blockNode, block *btcutil.Block, vi
 		}
 	}
 
+	scriptFlags |= txscript.ScriptStrictMultiSig
+
 	// Now that the inexpensive checks are done and have passed, verify the
 	// transactions are actually allowed to spend the coins by running the
 	// expensive ECDSA signature check scripts.  Doing this last helps
diff --git a/txscript/standard.go b/txscript/standard.go
index b8ffc42a6..561165074 100644
--- a/txscript/standard.go
+++ b/txscript/standard.go
@@ -38,6 +38,7 @@ const (
 		ScriptVerifyCheckLockTimeVerify |
 		ScriptVerifyCheckSequenceVerify |
 		ScriptVerifyLowS |
+		ScriptStrictMultiSig |
 		ScriptVerifyWitness |
 		ScriptVerifyDiscourageUpgradeableWitnessProgram
 )