diff --git a/scripts/decodetree.py b/scripts/decodetree.py
index 81874e22cc..d7a59d63ac 100755
--- a/scripts/decodetree.py
+++ b/scripts/decodetree.py
@@ -184,7 +184,7 @@ def str_extract(self):
         return '{0}(insn, {1}, {2})'.format(extr, self.pos, self.len)
 
     def __eq__(self, other):
-        return self.sign == other.sign and self.sign == other.sign
+        return self.sign == other.sign and self.mask == other.mask
 
     def __ne__(self, other):
         return not self.__eq__(other)