diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 2b33585e..a2f41f26 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -7,6 +7,11 @@ target_link_libraries (test-protocols ${LINK_LIBS})
 target_compile_options(test-protocols PRIVATE -Werror -Wall -Wextra)
 add_test (NAME "TestProtocols" COMMAND test-protocols)
 
+add_executable (test-utils utils.c ../src/bbl_utils.c)
+target_link_libraries (test-utils ${LINK_LIBS})
+target_compile_options(test-utils PRIVATE -Werror -Wall -Wextra)
+add_test (NAME "TestUtils" COMMAND test-utils)
+
 add_executable (test-decode-pcap protocols_decode_pcap.c ../src/bbl_protocols.c)
 target_link_libraries (test-decode-pcap ${LINK_LIBS})
 target_compile_options(test-decode-pcap PRIVATE -Werror -Wall -Wextra)
\ No newline at end of file
diff --git a/test/utils.c b/test/utils.c
new file mode 100644
index 00000000..7d368b08
--- /dev/null
+++ b/test/utils.c
@@ -0,0 +1,90 @@
+/*
+ * BNG Blaster (BBL) - Util Tests
+ *
+ * Christian Giese, June 2021
+ *
+ * Copyright (C) 2020-2021, RtBrick, Inc.
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#include <stddef.h>
+#include <stdarg.h>
+#include <setjmp.h>
+#include <cmocka.h>
+#include <bbl.h>
+#include <bbl_utils.h>
+
+static void
+test_val2key(void **unused) {
+    (void) unused;
+
+    struct keyval_ numbers[] = {
+        { 1, "one" },
+        { 2, "two" },
+        { 0, NULL}
+    };
+    assert_string_equal(val2key(numbers, 1), "one");
+    assert_string_equal(val2key(numbers, 2), "two");
+    assert_string_equal(val2key(numbers, 3), "Unknown");
+}
+
+static void
+test_format_mac_address(void **unused) {
+    (void) unused;
+
+    uint8_t mac[MAC_STR_LEN] = {0xa1, 0xb2, 0xc3, 0xd4, 0xe5, 0xf6};
+    assert_string_equal(format_mac_address(mac), "a1:b2:c3:d4:e5:f6");
+}
+
+static void
+test_format_ipv4_address(void **unused) {
+    (void) unused;
+
+    uint32_t ipv4 = htobe32(0x01020304);
+    assert_string_equal(format_ipv4_address(&ipv4), "1.2.3.4");
+}
+
+static void
+test_format_ipv6_address(void **unused) {
+    (void) unused;
+
+    ipv6addr_t ipv6 = {0};
+    ipv6[0] = 0xfe;
+    ipv6[1] = 0x80;
+    ipv6[15] = 0x01;
+
+    assert_string_equal(format_ipv6_address(&ipv6), "fe80::1");
+}
+
+static void
+test_format_ipv6_prefix(void **unused) {
+    (void) unused;
+
+    ipv6_prefix ipv6 = {0};
+    ipv6.len = 64;
+    ipv6.address[0] = 0xfe;
+    ipv6.address[1] = 0x80;
+    ipv6.address[15] = 0x01;
+
+    assert_string_equal(format_ipv6_prefix(&ipv6), "fe80::1/64");
+}
+
+static void
+test_replace_substring(void **unused) {
+    (void) unused;
+
+    assert_string_equal(replace_substring("1234{i}90", "{i}", "5678"), "1234567890"); 
+    assert_string_equal(replace_substring("{i1}{i2}{i2}", "{i2}", "2"), "{i1}22"); 
+    assert_string_equal(replace_substring("1234{long-variable-name}567890", "{long-variable-name}", ""), "1234567890"); 
+}
+
+int main() {
+    const struct CMUnitTest tests[] = {
+        cmocka_unit_test(test_val2key),
+        cmocka_unit_test(test_format_mac_address),
+        cmocka_unit_test(test_format_ipv4_address),
+        cmocka_unit_test(test_format_ipv6_address),
+        cmocka_unit_test(test_format_ipv6_prefix),
+        cmocka_unit_test(test_replace_substring),
+    };
+    return cmocka_run_group_tests(tests, NULL, NULL);
+}