diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 376e687..a9f1b1e 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -9,6 +9,7 @@ if(ENABLE_CJSON_TEST)
     set(unity_tests
         parse_examples
         parse_number
+        parse_hex4
     )
 
     foreach(unity_test ${unity_tests})
diff --git a/tests/parse_hex4.c b/tests/parse_hex4.c
new file mode 100644
index 0000000..286157f
--- /dev/null
+++ b/tests/parse_hex4.c
@@ -0,0 +1,73 @@
+/*
+  Copyright (c) 2009-2017 Dave Gamble and cJSON contributors
+
+  Permission is hereby granted, free of charge, to any person obtaining a copy
+  of this software and associated documentation files (the "Software"), to deal
+  in the Software without restriction, including without limitation the rights
+  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+  copies of the Software, and to permit persons to whom the Software is
+  furnished to do so, subject to the following conditions:
+
+  The above copyright notice and this permission notice shall be included in
+  all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+  THE SOFTWARE.
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "unity/examples/unity_config.h"
+#include "unity/src/unity.h"
+#include "../cJSON.c"
+
+static void parse_hex4_should_parse_all_combinations(void)
+{
+    unsigned int number = 0;
+    unsigned char digits_lower[5];
+    unsigned char digits_upper[5];
+    /* test all combinations */
+    for (number = 0; number <= 0xFFFF; number++)
+    {
+        TEST_ASSERT_EQUAL_INT_MESSAGE(4, sprintf((char*)digits_lower, "%.4x", number), "sprintf failed.");
+        TEST_ASSERT_EQUAL_INT_MESSAGE(4, sprintf((char*)digits_upper, "%.4X", number), "sprintf failed.");
+
+        TEST_ASSERT_EQUAL_INT_MESSAGE(number, parse_hex4(digits_lower), "Failed to parse lowercase digits.");
+        TEST_ASSERT_EQUAL_INT_MESSAGE(number, parse_hex4(digits_upper), "Failed to parse uppercase digits.");
+    }
+}
+
+static void parse_hex4_should_parse_mixed_case(void)
+{
+    TEST_ASSERT_EQUAL_INT(0xBEEF, parse_hex4((const unsigned char*)"beef"));
+    TEST_ASSERT_EQUAL_INT(0xBEEF, parse_hex4((const unsigned char*)"beeF"));
+    TEST_ASSERT_EQUAL_INT(0xBEEF, parse_hex4((const unsigned char*)"beEf"));
+    TEST_ASSERT_EQUAL_INT(0xBEEF, parse_hex4((const unsigned char*)"beEF"));
+    TEST_ASSERT_EQUAL_INT(0xBEEF, parse_hex4((const unsigned char*)"bEef"));
+    TEST_ASSERT_EQUAL_INT(0xBEEF, parse_hex4((const unsigned char*)"bEeF"));
+    TEST_ASSERT_EQUAL_INT(0xBEEF, parse_hex4((const unsigned char*)"bEEf"));
+    TEST_ASSERT_EQUAL_INT(0xBEEF, parse_hex4((const unsigned char*)"bEEF"));
+    TEST_ASSERT_EQUAL_INT(0xBEEF, parse_hex4((const unsigned char*)"Beef"));
+    TEST_ASSERT_EQUAL_INT(0xBEEF, parse_hex4((const unsigned char*)"BeeF"));
+    TEST_ASSERT_EQUAL_INT(0xBEEF, parse_hex4((const unsigned char*)"BeEf"));
+    TEST_ASSERT_EQUAL_INT(0xBEEF, parse_hex4((const unsigned char*)"BeEF"));
+    TEST_ASSERT_EQUAL_INT(0xBEEF, parse_hex4((const unsigned char*)"BEef"));
+    TEST_ASSERT_EQUAL_INT(0xBEEF, parse_hex4((const unsigned char*)"BEeF"));
+    TEST_ASSERT_EQUAL_INT(0xBEEF, parse_hex4((const unsigned char*)"BEEf"));
+    TEST_ASSERT_EQUAL_INT(0xBEEF, parse_hex4((const unsigned char*)"BEEF"));
+}
+
+int main(void)
+{
+    UNITY_BEGIN();
+    RUN_TEST(parse_hex4_should_parse_all_combinations);
+    RUN_TEST(parse_hex4_should_parse_mixed_case);
+    return UNITY_END();
+}