diff --git a/builtin-mailinfo.c b/builtin-mailinfo.c
index c95e477e83..489c2c58c0 100644
--- a/builtin-mailinfo.c
+++ b/builtin-mailinfo.c
@@ -851,8 +851,8 @@ static void handle_info(void)
 	fprintf(fout, "\n");
 }
 
-int mailinfo(FILE *in, FILE *out, int ks, const char *encoding,
-	     const char *msg, const char *patch)
+static int mailinfo(FILE *in, FILE *out, int ks, const char *encoding,
+		    const char *msg, const char *patch)
 {
 	keep_subject = ks;
 	metainfo_charset = encoding;
diff --git a/builtin-mailsplit.c b/builtin-mailsplit.c
index c938425555..43fc373a15 100644
--- a/builtin-mailsplit.c
+++ b/builtin-mailsplit.c
@@ -159,8 +159,8 @@ out:
 	return ret;
 }
 
-int split_mbox(const char *file, const char *dir, int allow_bare,
-		int nr_prec, int skip)
+static int split_mbox(const char *file, const char *dir, int allow_bare,
+		      int nr_prec, int skip)
 {
 	char name[PATH_MAX];
 	int ret = -1;
diff --git a/builtin.h b/builtin.h
index 39290d1b8e..fe8ba9e65f 100644
--- a/builtin.h
+++ b/builtin.h
@@ -7,8 +7,6 @@ extern const char git_version_string[];
 extern const char git_usage_string[];
 
 extern void help_unknown_cmd(const char *cmd);
-extern int mailinfo(FILE *in, FILE *out, int ks, const char *encoding, const char *msg, const char *patch);
-extern int split_mbox(const char *file, const char *dir, int allow_bare, int nr_prec, int skip);
 extern void stripspace(FILE *in, FILE *out);
 extern int write_tree(unsigned char *sha1, int missing_ok, const char *prefix);
 extern void prune_packed_objects(int);