diff --git a/lib/script/script.js b/lib/script/script.js
index b08e8f45..e00d09ba 100644
--- a/lib/script/script.js
+++ b/lib/script/script.js
@@ -2888,7 +2888,8 @@ Script.verifyProgram = function verifyProgram(witness, output, flags, tx, index,
       throw new ScriptError('WITNESS_PROGRAM_WRONG_LENGTH');
     }
   } else if ((flags & Script.flags.VERIFY_MAST) && program.version === 1) {
-    return Script.verifyMast(program, stack, output, flags, tx, index);
+    Script.verifyMast(program, stack, output, flags, tx, index);
+    return;
   } else {
     // Anyone can spend (we can return true here
     // if we want to always relay these transactions).
@@ -2899,7 +2900,7 @@ Script.verifyProgram = function verifyProgram(witness, output, flags, tx, index,
     // due to VERIFY_CLEANSTACK.
     if (flags & Script.flags.VERIFY_DISCOURAGE_UPGRADABLE_WITNESS_PROGRAM)
       throw new ScriptError('DISCOURAGE_UPGRADABLE_WITNESS_PROGRAM');
-    return true;
+    return;
   }
 
   // Witnesses still have push limits.