diff --git a/builtin-fetch.c b/builtin-fetch.c
index ee93d3a93da0267caa485fa552c29d779aecfdf7..57c161d35b2e317f1fe32f39067c86508b89152e 100644
--- a/builtin-fetch.c
+++ b/builtin-fetch.c
@@ -534,6 +534,19 @@ static void find_non_local_tags(struct transport *transport,
 	string_list_clear(&new_refs, 0);
 }
 
+static void check_not_current_branch(struct ref *ref_map)
+{
+	struct branch *current_branch = branch_get(NULL);
+
+	if (is_bare_repository() || !current_branch)
+		return;
+
+	for (; ref_map; ref_map = ref_map->next)
+		if (ref_map->peer_ref && !strcmp(current_branch->refname,
+					ref_map->peer_ref->name))
+			die("Refusing to fetch into current branch");
+}
+
 static int do_fetch(struct transport *transport,
 		    struct refspec *refs, int ref_count)
 {
@@ -558,6 +571,8 @@ static int do_fetch(struct transport *transport,
 	}
 
 	ref_map = get_ref_map(transport, refs, ref_count, tags, &autotags);
+	if (!update_head_ok)
+		check_not_current_branch(ref_map);
 
 	for (rm = ref_map; rm; rm = rm->next) {
 		if (rm->peer_ref)
diff --git a/t/t5405-send-pack-rewind.sh b/t/t5405-send-pack-rewind.sh
index 86abc6227105e27fdb9ad99e34193efb90a6242f..cb9aacc7bc62e2ecfdca0dc7f6071e5330fe09d0 100755
--- a/t/t5405-send-pack-rewind.sh
+++ b/t/t5405-send-pack-rewind.sh
@@ -12,7 +12,7 @@ test_expect_success setup '
 	mkdir another && (
 		cd another &&
 		git init &&
-		git fetch .. master:master
+		git fetch --update-head-ok .. master:master
 	) &&
 
 	>file2 && git add file2 && test_tick &&
diff --git a/t/t5505-remote.sh b/t/t5505-remote.sh
index c4496635dfba85b0e9fc105c4516096d433881a4..0103e1a18046b6a156721da0036155b2f707b9f6 100755
--- a/t/t5505-remote.sh
+++ b/t/t5505-remote.sh
@@ -188,7 +188,7 @@ test_expect_success 'prune --dry-run' '
 test_expect_success 'add --mirror && prune' '
 	(mkdir mirror &&
 	 cd mirror &&
-	 git init &&
+	 git init --bare &&
 	 git remote add --mirror -f origin ../one) &&
 	(cd one &&
 	 git branch -m side2 side) &&
diff --git a/t/t5510-fetch.sh b/t/t5510-fetch.sh
index de26c203270522983f9ffae4e0bde64a61898567..52094e78dcd63cd7dc1ce166450c403fc32efbac 100755
--- a/t/t5510-fetch.sh
+++ b/t/t5510-fetch.sh
@@ -303,4 +303,16 @@ test_expect_success 'pushing nonexistent branch by mistake should not segv' '
 
 '
 
+test_expect_success 'refuse to fetch into the current branch' '
+
+	test_must_fail git fetch . side:master
+
+'
+
+test_expect_success 'fetch into the current branch with --update-head-ok' '
+
+	git fetch --update-head-ok . side:master
+
+'
+
 test_done
diff --git a/t/t9300-fast-import.sh b/t/t9300-fast-import.sh
index c6bc0a607f200fcc8888b66ff1a8f0e324332db8..dba3a1b48f70c47b405d85f140684b181e62002a 100755
--- a/t/t9300-fast-import.sh
+++ b/t/t9300-fast-import.sh
@@ -983,7 +983,7 @@ test_expect_success \
 	 git checkout subuse1 &&
 	 rm -rf sub && mkdir sub && cd sub &&
 	 git init &&
-	 git fetch .. refs/heads/sub:refs/heads/master &&
+	 git fetch --update-head-ok .. refs/heads/sub:refs/heads/master &&
 	 git checkout master &&
 	 cd .. &&
 	 git submodule init &&