diff --git a/spacy/morphology.pyx b/spacy/morphology.pyx
index d37362bed..f13de4735 100644
--- a/spacy/morphology.pyx
+++ b/spacy/morphology.pyx
@@ -36,7 +36,7 @@ cdef class Morphology:
 
     cdef shared_ptr[MorphAnalysisC] _lookup_tag(self, hash_t tag_hash):
         match = self.tags.find(tag_hash)
-        if match != self.tags.const_end():
+        if match != self.tags.end():
             return deref(match).second
         else:
             return shared_ptr[MorphAnalysisC]()