diff --git a/refs.c b/refs.c
index c13b8ff6d8..9abd9e5b86 100644
--- a/refs.c
+++ b/refs.c
@@ -1263,6 +1263,13 @@ int ref_transaction_update(struct ref_transaction *transaction,
 		return -1;
 	}
 
+	if (!(flags & REF_SKIP_REFNAME_VERIFICATION) &&
+	    is_pseudo_ref(refname)) {
+		strbuf_addf(err, _("refusing to update pseudoref '%s'"),
+			    refname);
+		return -1;
+	}
+
 	if (flags & ~REF_TRANSACTION_UPDATE_ALLOWED_FLAGS)
 		BUG("illegal flags 0x%x passed to ref_transaction_update()", flags);
 
diff --git a/t/t5510-fetch.sh b/t/t5510-fetch.sh
index 33d34d5ae9..4eb569f4df 100755
--- a/t/t5510-fetch.sh
+++ b/t/t5510-fetch.sh
@@ -518,7 +518,7 @@ test_expect_success 'fetch with a non-applying branch.<name>.merge' '
 test_expect_success 'fetch from GIT URL with a non-applying branch.<name>.merge [1]' '
 	one_head=$(cd one && git rev-parse HEAD) &&
 	this_head=$(git rev-parse HEAD) &&
-	git update-ref -d FETCH_HEAD &&
+	rm .git/FETCH_HEAD &&
 	git fetch one &&
 	test $one_head = "$(git rev-parse --verify FETCH_HEAD)" &&
 	test $this_head = "$(git rev-parse --verify HEAD)"
@@ -530,7 +530,7 @@ test_expect_success 'fetch from GIT URL with a non-applying branch.<name>.merge
 	one_ref=$(cd one && git symbolic-ref HEAD) &&
 	git config branch.main.remote blub &&
 	git config branch.main.merge "$one_ref" &&
-	git update-ref -d FETCH_HEAD &&
+	rm .git/FETCH_HEAD &&
 	git fetch one &&
 	test $one_head = "$(git rev-parse --verify FETCH_HEAD)" &&
 	test $this_head = "$(git rev-parse --verify HEAD)"
@@ -540,7 +540,7 @@ test_expect_success 'fetch from GIT URL with a non-applying branch.<name>.merge
 # the merge spec does not match the branch the remote HEAD points to
 test_expect_success 'fetch from GIT URL with a non-applying branch.<name>.merge [3]' '
 	git config branch.main.merge "${one_ref}_not" &&
-	git update-ref -d FETCH_HEAD &&
+	rm .git/FETCH_HEAD &&
 	git fetch one &&
 	test $one_head = "$(git rev-parse --verify FETCH_HEAD)" &&
 	test $this_head = "$(git rev-parse --verify HEAD)"