diff --git a/object.c b/object.c
index b9a4a0e501..0afdfd19b7 100644
--- a/object.c
+++ b/object.c
@@ -434,3 +434,14 @@ void clear_object_flags(unsigned flags)
 			obj->flags &= ~flags;
 	}
 }
+
+void clear_commit_marks_all(unsigned int flags)
+{
+	int i;
+
+	for (i = 0; i < obj_hash_size; i++) {
+		struct object *obj = obj_hash[i];
+		if (obj && obj->type == OBJ_COMMIT)
+			obj->flags &= ~flags;
+	}
+}
diff --git a/object.h b/object.h
index df8abe96f7..1111f64dd9 100644
--- a/object.h
+++ b/object.h
@@ -148,4 +148,9 @@ void object_array_clear(struct object_array *array);
 
 void clear_object_flags(unsigned flags);
 
+/*
+ * Clear the specified object flags from all in-core commit objects.
+ */
+extern void clear_commit_marks_all(unsigned int flags);
+
 #endif /* OBJECT_H */