diff --git a/src/test/include.am b/src/test/include.am
index 1055cd0a81..dd2986c67c 100644
--- a/src/test/include.am
+++ b/src/test/include.am
@@ -182,6 +182,7 @@ src_test_test_SOURCES += \
 	src/test/test_x509.c \
 	src/test/test_helpers.c \
 	src/test/test_dns.c \
+	src/test/test_parsecommon.c \
 	src/test/testing_common.c \
 	src/test/testing_rsakeys.c \
 	src/ext/tinytest.c
diff --git a/src/test/test.c b/src/test/test.c
index 70d91e3967..56eb153289 100644
--- a/src/test/test.c
+++ b/src/test/test.c
@@ -926,5 +926,6 @@ struct testgroup_t testgroups[] = {
   { "util/thread/", thread_tests },
   { "util/handle/", handle_tests },
   { "dns/", dns_tests },
+  { "parsecommon/", parsecommon_tests },
   END_OF_GROUPS
 };
diff --git a/src/test/test.h b/src/test/test.h
index a46fedf3e0..281551aa69 100644
--- a/src/test/test.h
+++ b/src/test/test.h
@@ -266,6 +266,7 @@ extern struct testcase_t dns_tests[];
 extern struct testcase_t handle_tests[];
 extern struct testcase_t sr_tests[];
 extern struct testcase_t x509_tests[];
+extern struct testcase_t parsecommon_tests[];
 
 extern struct testcase_t slow_crypto_tests[];
 extern struct testcase_t slow_util_tests[];
diff --git a/src/test/test_parsecommon.c b/src/test/test_parsecommon.c
new file mode 100644
index 0000000000..f152450f5a
--- /dev/null
+++ b/src/test/test_parsecommon.c
@@ -0,0 +1,44 @@
+/* Copyright (c) 2001-2004, Roger Dingledine.
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2018, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+#include "core/or/or.h"
+#include "test/test.h"
+#include "lib/memarea/memarea.h"
+#include "lib/encoding/binascii.h"
+#include "feature/dirparse/parsecommon.h"
+#include "test/log_test_helpers.h"
+
+static void
+test_parsecommon_tokenize_string_null(void *arg)
+{
+
+  memarea_t *area = memarea_new();
+  smartlist_t *tokens = smartlist_new();
+
+  (void)arg;
+
+  const char *str_with_null = "a\0bccccccccc";
+
+  int retval =
+  tokenize_string(area, str_with_null,
+                  str_with_null + 3,
+                  tokens, NULL, 0);
+
+  tt_int_op(retval, OP_EQ, -1);
+
+ done:
+  memarea_drop_all(area);
+  smartlist_free(tokens);
+  return;
+}
+
+#define PARSECOMMON_TEST(name) \
+  { #name, test_parsecommon_ ## name, 0, NULL, NULL }
+
+struct testcase_t parsecommon_tests[] = {
+  PARSECOMMON_TEST(tokenize_string_null),
+  END_OF_TESTCASES
+};
+