diff --git a/spacy/tokens/doc.pyx b/spacy/tokens/doc.pyx
index 7bed0cd7d..91ab1d8a8 100644
--- a/spacy/tokens/doc.pyx
+++ b/spacy/tokens/doc.pyx
@@ -451,10 +451,7 @@ cdef class Doc:
             cdef int i
             for i in range(self.length):
                 self.c[i].ent_type = 0
-                # At this point we don't know whether the NER has run over the
-                # Doc. If the ent_iob is missing, leave it missing.
-                if self.c[i].ent_iob != 0:
-                    self.c[i].ent_iob = 2  # Means O. Non-O are set from ents.
+                self.c[i].ent_iob = 0  # Means missing.
             cdef attr_t ent_type
             cdef int start, end
             for ent_info in ents: