diff --git a/cgit.h b/cgit.h
index ea90833..c99d337 100644
--- a/cgit.h
+++ b/cgit.h
@@ -61,6 +61,7 @@ struct cgit_repo {
 	int snapshots;
 	int enable_log_filecount;
 	int enable_log_linecount;
+	time_t mtime;
 };
 
 struct cgit_repolist {
diff --git a/shared.c b/shared.c
index f5875e4..89d1bab 100644
--- a/shared.c
+++ b/shared.c
@@ -60,6 +60,7 @@ struct cgit_repo *cgit_add_repo(const char *url)
 	ret->enable_log_linecount = ctx.cfg.enable_log_linecount;
 	ret->module_link = ctx.cfg.module_link;
 	ret->readme = NULL;
+	ret->mtime = -1;
 	return ret;
 }
 
diff --git a/ui-repolist.c b/ui-repolist.c
index cf27cb3..aa743bf 100644
--- a/ui-repolist.c
+++ b/ui-repolist.c
@@ -32,19 +32,27 @@ static int get_repo_modtime(const struct cgit_repo *repo, time_t *mtime)
 {
 	char *path;
 	struct stat s;
+	struct cgit_repo *r = (struct cgit_repo *)repo;
 
+	if (repo->mtime != -1) {
+		*mtime = repo->mtime;
+		return 1;
+	}
 	path = fmt("%s/%s", repo->path, ctx.cfg.agefile);
 	if (stat(path, &s) == 0) {
 		*mtime = read_agefile(path);
+		r->mtime = *mtime;
 		return 1;
 	}
 
 	path = fmt("%s/refs/heads/%s", repo->path, repo->defbranch);
-	if (stat(path, &s) == 0) {
+	if (stat(path, &s) == 0)
 		*mtime = s.st_mtime;
-		return 1;
-	}
-	return 0;
+	else
+		*mtime = 0;
+
+	r->mtime = *mtime;
+	return (r->mtime != 0);
 }
 
 static void print_modtime(struct cgit_repo *repo)