diff --git a/refs.c b/refs.c
index 33ced65a78..024211d72b 100644
--- a/refs.c
+++ b/refs.c
@@ -1453,7 +1453,7 @@ int read_ref_at(const char *ref, unsigned long at_time, int cnt, unsigned char *
 	return 1;
 }
 
-int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
+int for_each_recent_reflog_ent(const char *ref, each_reflog_ent_fn fn, long ofs, void *cb_data)
 {
 	const char *logfile;
 	FILE *logfp;
@@ -1464,6 +1464,16 @@ int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
 	logfp = fopen(logfile, "r");
 	if (!logfp)
 		return -1;
+
+	if (ofs) {
+		struct stat statbuf;
+		if (fstat(fileno(logfp), &statbuf) ||
+		    statbuf.st_size < ofs ||
+		    fseek(logfp, -ofs, SEEK_END) ||
+		    fgets(buf, sizeof(buf), logfp))
+			return -1;
+	}
+
 	while (fgets(buf, sizeof(buf), logfp)) {
 		unsigned char osha1[20], nsha1[20];
 		char *email_end, *message;
@@ -1497,6 +1507,11 @@ int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
 	return ret;
 }
 
+int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
+{
+	return for_each_recent_reflog_ent(ref, fn, 0, cb_data);
+}
+
 static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data)
 {
 	DIR *dir = opendir(git_path("logs/%s", base));
diff --git a/refs.h b/refs.h
index 06ad260556..3bb529d387 100644
--- a/refs.h
+++ b/refs.h
@@ -60,6 +60,7 @@ extern int read_ref_at(const char *ref, unsigned long at_time, int cnt, unsigned
 /* iterate over reflog entries */
 typedef int each_reflog_ent_fn(unsigned char *osha1, unsigned char *nsha1, const char *, unsigned long, int, const char *, void *);
 int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data);
+int for_each_recent_reflog_ent(const char *ref, each_reflog_ent_fn fn, long, void *cb_data);
 
 /*
  * Calls the specified function for each reflog file until it returns nonzero,
diff --git a/sha1_name.c b/sha1_name.c
index 4c0370bb79..38c9f1b19e 100644
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -775,7 +775,13 @@ int interpret_nth_last_branch(const char *name, struct strbuf *buf)
 		strbuf_init(&cb.buf[i], 20);
 	cb.cnt = 0;
 	retval = 0;
-	for_each_reflog_ent("HEAD", grab_nth_branch_switch, &cb);
+	for_each_recent_reflog_ent("HEAD", grab_nth_branch_switch, 40960, &cb);
+	if (cb.cnt < nth) {
+		cb.cnt = 0;
+		for (i = 0; i < nth; i++)
+			strbuf_release(&cb.buf[i]);
+		for_each_reflog_ent("HEAD", grab_nth_branch_switch, &cb);
+	}
 	if (cb.cnt < nth)
 		goto release_return;
 	i = cb.cnt % nth;