diff --git a/refs.c b/refs.c
index 8c9490235ea..8b9f7c3a80a 100644
--- a/refs.c
+++ b/refs.c
@@ -2010,7 +2010,7 @@ int peel_iterated_oid(const struct object_id *base, struct object_id *peeled)
 	     oideq(current_ref_iter->oid, base)))
 		return ref_iterator_peel(current_ref_iter, peeled);
 
-	return peel_object(base, peeled);
+	return peel_object(base, peeled) ? -1 : 0;
 }
 
 int refs_create_symref(struct ref_store *refs,
diff --git a/refs/packed-backend.c b/refs/packed-backend.c
index dfecdbc1db6..66cb90c79ee 100644
--- a/refs/packed-backend.c
+++ b/refs/packed-backend.c
@@ -889,7 +889,7 @@ static int packed_ref_iterator_peel(struct ref_iterator *ref_iterator,
 	} else if ((iter->base.flags & (REF_ISBROKEN | REF_ISSYMREF))) {
 		return -1;
 	} else {
-		return !!peel_object(&iter->oid, peeled);
+		return peel_object(&iter->oid, peeled) ? -1 : 0;
 	}
 }
 
diff --git a/refs/ref-cache.c b/refs/ref-cache.c
index 46f1e542843..49d732f6db9 100644
--- a/refs/ref-cache.c
+++ b/refs/ref-cache.c
@@ -491,7 +491,7 @@ static int cache_ref_iterator_advance(struct ref_iterator *ref_iterator)
 static int cache_ref_iterator_peel(struct ref_iterator *ref_iterator,
 				   struct object_id *peeled)
 {
-	return peel_object(ref_iterator->oid, peeled);
+	return peel_object(ref_iterator->oid, peeled) ? -1 : 0;
 }
 
 static int cache_ref_iterator_abort(struct ref_iterator *ref_iterator)
diff --git a/refs/refs-internal.h b/refs/refs-internal.h
index 467f4b3c936..3155708345f 100644
--- a/refs/refs-internal.h
+++ b/refs/refs-internal.h
@@ -453,6 +453,9 @@ void base_ref_iterator_free(struct ref_iterator *iter);
  */
 typedef int ref_iterator_advance_fn(struct ref_iterator *ref_iterator);
 
+/*
+ * Peels the current ref, returning 0 for success or -1 for failure.
+ */
 typedef int ref_iterator_peel_fn(struct ref_iterator *ref_iterator,
 				 struct object_id *peeled);