diff --git a/mempool.go b/mempool.go
index bc867b97a..83fe19054 100644
--- a/mempool.go
+++ b/mempool.go
@@ -271,6 +271,16 @@ func checkTransactionStandard(tx *btcutil.Tx, height int64) error {
 				"script is not push only", i)
 			return TxRuleError(str)
 		}
+
+		// Each transaction input signature script must only contain
+		// canonical data pushes.  A canonical data push is one where
+		// the minimum possible number of bytes is used to represent
+		// the data push as possible.
+		if !btcscript.HasCanonicalPushes(txIn.SignatureScript) {
+			str := fmt.Sprintf("transaction input %d: signature "+
+				"script has a non-canonical data push", i)
+			return TxRuleError(str)
+		}
 	}
 
 	// None of the output public key scripts can be a non-standard script or