diff --git a/spacy/kb/kb.pxd b/spacy/kb/kb.pxd
index ff2fc15ce..9330dd5df 100644
--- a/spacy/kb/kb.pxd
+++ b/spacy/kb/kb.pxd
@@ -7,4 +7,4 @@ from ..vocab cimport Vocab
 cdef class KnowledgeBase:
     cdef Pool mem
     cdef readonly Vocab vocab
-    cdef int64_t entity_vector_length
+    cpdef int64_t entity_vector_length