diff --git a/tests/unit_tests/openvpn/test_packet_id.c b/tests/unit_tests/openvpn/test_packet_id.c
index a24580b..312a6b3d 100644
--- a/tests/unit_tests/openvpn/test_packet_id.c
+++ b/tests/unit_tests/openvpn/test_packet_id.c
@@ -238,7 +238,8 @@
     uint8_t expected_header_48[8] = { 0xff, 0xfe, 0xfa, 0x07, 0x9a, 0xb9, 0xd2, 0xe9};
     assert_memory_equal(BPTR(&buf_48), expected_header_48, 8);
 
-    /* test writing/checking the 48 bit overflow */
+    /* test writing/checking the 48 bit per epoch packet counter
+     * overflow */
     data->pis.id = 0xfffffffffffe;
     struct buffer buf_of = alloc_buf_gc(128, &data->gc);
     assert_true(packet_id_write_epoch(&data->pis, 0xf00f, &buf_of));