diff --git a/builtin/blame.c b/builtin/blame.c
index 6f7e32411a..d48dbbd005 100644
--- a/builtin/blame.c
+++ b/builtin/blame.c
@@ -60,7 +60,7 @@ static int mark_ignored_lines;
 static struct date_mode blame_date_mode = { DATE_ISO8601 };
 static size_t blame_date_width;
 
-static struct string_list mailmap = STRING_LIST_INIT_NODUP;
+static struct mailmap mailmap;
 
 #ifndef DEBUG_BLAME
 #define DEBUG_BLAME 0
diff --git a/builtin/check-mailmap.c b/builtin/check-mailmap.c
index cdce144f3b..ad155e9092 100644
--- a/builtin/check-mailmap.c
+++ b/builtin/check-mailmap.c
@@ -15,7 +15,7 @@ static const struct option check_mailmap_options[] = {
 	OPT_END()
 };
 
-static void check_mailmap(struct string_list *mailmap, const char *contact)
+static void check_mailmap(struct mailmap *mailmap, const char *contact)
 {
 	const char *name, *mail;
 	size_t namelen, maillen;
@@ -39,7 +39,7 @@ static void check_mailmap(struct string_list *mailmap, const char *contact)
 int cmd_check_mailmap(int argc, const char **argv, const char *prefix)
 {
 	int i;
-	struct string_list mailmap = STRING_LIST_INIT_NODUP;
+	struct mailmap mailmap;
 
 	git_config(git_default_config, NULL);
 	argc = parse_options(argc, argv, prefix, check_mailmap_options,
diff --git a/builtin/commit.c b/builtin/commit.c
index 505fe60956..2d69847c49 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -1027,7 +1027,7 @@ static const char *find_author_by_nickname(const char *name)
 	struct rev_info revs;
 	struct commit *commit;
 	struct strbuf buf = STRBUF_INIT;
-	struct string_list mailmap = STRING_LIST_INIT_NODUP;
+	struct mailmap mailmap;
 	const char *av[20];
 	int ac = 0;
 
diff --git a/mailmap.c b/mailmap.c
index c9a538f4e2..d3287b409a 100644
--- a/mailmap.c
+++ b/mailmap.c
@@ -237,11 +237,14 @@ static int read_mailmap_blob(struct string_list *map,
 	return 0;
 }
 
-int read_mailmap(struct string_list *map, char **repo_abbrev)
+int read_mailmap(struct mailmap *mailmap, char **repo_abbrev)
 {
 	int err = 0;
+	struct string_list *map;
+
+	map = mailmap->mailmap = malloc(sizeof(*mailmap->mailmap));
+	string_list_init(map, 1);
 
-	map->strdup_strings = 1;
 	map->cmp = namemap_cmp;
 
 	if (!git_mailmap_blob && is_bare_repository())
@@ -254,11 +257,14 @@ int read_mailmap(struct string_list *map, char **repo_abbrev)
 	return err;
 }
 
-void clear_mailmap(struct string_list *map)
+void clear_mailmap(struct mailmap *mailmap)
 {
+	struct string_list *map = mailmap->mailmap;
 	debug_mm("mailmap: clearing %d entries...\n", map->nr);
 	map->strdup_strings = 1;
 	string_list_clear_func(map, free_mailmap_entry);
+	string_list_clear(map, 1);
+	free(map);
 	debug_mm("mailmap: cleared\n");
 }
 
@@ -313,7 +319,7 @@ static struct string_list_item *lookup_prefix(struct string_list *map,
 	return NULL;
 }
 
-int map_user(struct string_list *map,
+int map_user(struct mailmap *map,
 	     const char **email, size_t *emaillen,
 	     const char **name, size_t *namelen)
 {
@@ -324,7 +330,7 @@ int map_user(struct string_list *map,
 		 (int)*namelen, debug_str(*name),
 		 (int)*emaillen, debug_str(*email));
 
-	item = lookup_prefix(map, *email, *emaillen);
+	item = lookup_prefix(map->mailmap, *email, *emaillen);
 	if (item != NULL) {
 		me = (struct mailmap_entry *)item->util;
 		if (me->namemap.nr) {
@@ -362,7 +368,7 @@ int map_user(struct string_list *map,
 	return 0;
 }
 
-int mailmap_entries(struct string_list *map)
+int mailmap_entries(struct mailmap *map)
 {
-	return map->nr;
+	return map->mailmap->nr;
 }
diff --git a/mailmap.h b/mailmap.h
index ff57b05a15..4cdce3b064 100644
--- a/mailmap.h
+++ b/mailmap.h
@@ -1,13 +1,17 @@
 #ifndef MAILMAP_H
 #define MAILMAP_H
 
-struct string_list;
+#include "string-list.h"
 
-int read_mailmap(struct string_list *map, char **repo_abbrev);
-void clear_mailmap(struct string_list *map);
-int mailmap_entries(struct string_list *map);
+struct mailmap {
+	struct string_list *mailmap;
+};
 
-int map_user(struct string_list *map,
+int read_mailmap(struct mailmap *map, char **repo_abbrev);
+void clear_mailmap(struct mailmap *map);
+int mailmap_entries(struct mailmap *map);
+
+int map_user(struct mailmap *map,
 			 const char **email, size_t *emaillen, const char **name, size_t *namelen);
 
 #endif
diff --git a/pretty.c b/pretty.c
index 43a0039870..0dc2c98e4a 100644
--- a/pretty.c
+++ b/pretty.c
@@ -676,7 +676,7 @@ const char *repo_logmsg_reencode(struct repository *r,
 static int mailmap_name(const char **email, size_t *email_len,
 			const char **name, size_t *name_len)
 {
-	static struct string_list *mail_map;
+	static struct mailmap *mail_map;
 	if (!mail_map) {
 		mail_map = xcalloc(1, sizeof(*mail_map));
 		read_mailmap(mail_map, NULL);
diff --git a/pretty.h b/pretty.h
index 7ce6c0b437..15735a4c51 100644
--- a/pretty.h
+++ b/pretty.h
@@ -40,7 +40,7 @@ struct pretty_print_context {
 	struct reflog_walk_info *reflog_info;
 	struct rev_info *rev;
 	const char *output_encoding;
-	struct string_list *mailmap;
+	struct mailmap *mailmap;
 	int color;
 	struct ident_split *from_ident;
 	unsigned encode_email_headers:1;
diff --git a/revision.c b/revision.c
index 9dff845bed..848f43d88b 100644
--- a/revision.c
+++ b/revision.c
@@ -3659,7 +3659,7 @@ int rewrite_parents(struct rev_info *revs, struct commit *commit,
 	return 0;
 }
 
-static int commit_rewrite_person(struct strbuf *buf, const char *what, struct string_list *mailmap)
+static int commit_rewrite_person(struct strbuf *buf, const char *what, struct mailmap *mailmap)
 {
 	char *person, *endp;
 	size_t len, namelen, maillen;
diff --git a/revision.h b/revision.h
index 086ff10280..06bc127e90 100644
--- a/revision.h
+++ b/revision.h
@@ -7,6 +7,7 @@
 #include "notes.h"
 #include "pretty.h"
 #include "diff.h"
+#include "mailmap.h"
 #include "commit-slab-decl.h"
 
 /**
@@ -241,7 +242,7 @@ struct rev_info {
 	int		patch_name_max;
 	int		no_inline;
 	int		show_log_size;
-	struct string_list *mailmap;
+	struct mailmap *mailmap;
 
 	/* Filter by commit log message */
 	struct grep_opt	grep_filter;
diff --git a/shortlog.h b/shortlog.h
index 64be879b24..9ebf7bbb9c 100644
--- a/shortlog.h
+++ b/shortlog.h
@@ -2,6 +2,7 @@
 #define SHORTLOG_H
 
 #include "string-list.h"
+#include "mailmap.h"
 
 struct commit;
 
@@ -25,7 +26,7 @@ struct shortlog {
 
 	char *common_repo_prefix;
 	int email;
-	struct string_list mailmap;
+	struct mailmap mailmap;
 	FILE *file;
 };
 
