diff --git a/src/script/standard.h b/src/script/standard.h
--- a/src/script/standard.h
+++ b/src/script/standard.h
@@ -41,7 +41,9 @@
  */
 static const uint32_t MANDATORY_SCRIPT_VERIFY_FLAGS =
     SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_STRICTENC |
-    SCRIPT_ENABLE_SIGHASH_FORKID | SCRIPT_VERIFY_LOW_S | SCRIPT_VERIFY_NULLFAIL;
+    SCRIPT_ENABLE_SIGHASH_FORKID | SCRIPT_VERIFY_LOW_S |
+    SCRIPT_VERIFY_NULLFAIL | SCRIPT_VERIFY_SIGPUSHONLY |
+    SCRIPT_VERIFY_CLEANSTACK;
 
 enum txnouttype {
     TX_NONSTANDARD,