diff --git a/commit.c b/commit.c
index dc0c5bfdab..c99db162a4 100644
--- a/commit.c
+++ b/commit.c
@@ -160,7 +160,7 @@ struct commit_graft *read_graft_line(char *buf, int len)
 	return graft;
 }
 
-int read_graft_file(const char *graft_file)
+static int read_graft_file(const char *graft_file)
 {
 	FILE *fp = fopen(graft_file, "r");
 	char buf[1024];
diff --git a/commit.h b/commit.h
index de15f4d715..4c05864fb4 100644
--- a/commit.h
+++ b/commit.h
@@ -118,7 +118,6 @@ struct commit_graft {
 
 struct commit_graft *read_graft_line(char *buf, int len);
 int register_commit_graft(struct commit_graft *, int);
-int read_graft_file(const char *graft_file);
 struct commit_graft *lookup_commit_graft(const unsigned char *sha1);
 
 extern struct commit_list *get_merge_bases(struct commit *rev1, struct commit *rev2, int cleanup);