diff --git a/spacy/ml/models/coref_util.py b/spacy/ml/models/coref_util.py
index bd577e65f..9281ad0c7 100644
--- a/spacy/ml/models/coref_util.py
+++ b/spacy/ml/models/coref_util.py
@@ -143,7 +143,7 @@ def create_head_span_idxs(ops, doclen: int):
 
 
 def get_clusters_from_doc(doc) -> List[List[Tuple[int, int]]]:
-    """Given a Doc, convert the cluster spans to simple int tuple lists. The 
+    """Given a Doc, convert the cluster spans to simple int tuple lists. The
     ints are char spans, to be tokenization independent.
     """
     out = []
@@ -203,3 +203,15 @@ def create_gold_scores(
 
     # caller needs to convert to array, and add placeholder
     return out
+
+
+def spans2ints(doc):
+    """Convert doc.spans to nested list of ints for comparison.
+    The ints are token indices.
+
+    This is useful for checking consistency of predictions.
+    """
+    out = []
+    for key, cluster in doc.spans.items():
+        out.append([(ss.start, ss.end) for ss in cluster])
+    return out
diff --git a/spacy/tests/pipeline/test_coref.py b/spacy/tests/pipeline/test_coref.py
index 4b8ca1653..3bde6ad34 100644
--- a/spacy/tests/pipeline/test_coref.py
+++ b/spacy/tests/pipeline/test_coref.py
@@ -9,6 +9,7 @@ from spacy.ml.models.coref_util import (
     DEFAULT_CLUSTER_PREFIX,
     select_non_crossing_spans,
     get_sentence_ids,
+    spans2ints,
 )
 
 from thinc.util import has_torch
@@ -35,16 +36,6 @@ TRAIN_DATA = [
 # fmt: on
 
 
-def spans2ints(doc):
-    """Convert doc.spans to nested list of ints for comparison.
-    The ints are token indices.
-
-    This is useful for checking consistency of predictions.
-    """
-    out = []
-    for key, cluster in doc.spans.items():
-        out.append([(ss.start, ss.end) for ss in cluster])
-    return out
 
 
 @pytest.fixture