diff --git a/commit-graph.c b/commit-graph.c
index f83f6d2373..e77b19971d 100644
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -314,7 +314,7 @@ static int find_commit_in_graph(struct commit *item, struct commit_graph *g, uin
 	}
 }
 
-int parse_commit_in_graph(struct commit *item)
+static int parse_commit_in_graph_one(struct commit_graph *g, struct commit *item)
 {
 	uint32_t pos;
 
@@ -322,9 +322,21 @@ int parse_commit_in_graph(struct commit *item)
 		return 0;
 	if (item->object.parsed)
 		return 1;
+
+	if (find_commit_in_graph(item, g, &pos))
+		return fill_commit_in_graph(item, g, pos);
+
+	return 0;
+}
+
+int parse_commit_in_graph(struct commit *item)
+{
+	if (!core_commit_graph)
+		return 0;
+
 	prepare_commit_graph();
-	if (commit_graph && find_commit_in_graph(item, commit_graph, &pos))
-		return fill_commit_in_graph(item, commit_graph, pos);
+	if (commit_graph)
+		return parse_commit_in_graph_one(commit_graph, item);
 	return 0;
 }