diff --git a/spacy/tokens/doc.pyx b/spacy/tokens/doc.pyx
index c2853f2d5..7dfe0ca9f 100644
--- a/spacy/tokens/doc.pyx
+++ b/spacy/tokens/doc.pyx
@@ -528,9 +528,9 @@ cdef class Doc:
         doc (Doc): The parent document.
         start_idx (int): The index of the first character of the span.
         end_idx (int): The index of the first character after the span.
-        label (uint64 or string): A label to attach to the Span, e.g. for
+        label (Union[int, str]): A label to attach to the Span, e.g. for
             named entities.
-        kb_id (uint64 or string):  An ID from a KB to capture the meaning of a
+        kb_id (Union[int, str]):  An ID from a KB to capture the meaning of a
             named entity.
         vector (ndarray[ndim=1, dtype='float32']): A meaning representation of
             the span.
@@ -539,7 +539,7 @@ cdef class Doc:
             with token boundaries), "contract" (span of all tokens completely
             within the character span), "expand" (span of all tokens at least
             partially covered by the character span). Defaults to "strict".
-        span_id (uint64 or string): An identifier to associate with the span.
+        span_id (Union[int, str]): An identifier to associate with the span.
         RETURNS (Span): The newly constructed object.
 
         DOCS: https://spacy.io/api/doc#char_span