diff --git a/tests/unit/core/test-core-string.cpp b/tests/unit/core/test-core-string.cpp
index 62fa5ec39..892e44f30 100644
--- a/tests/unit/core/test-core-string.cpp
+++ b/tests/unit/core/test-core-string.cpp
@@ -141,12 +141,36 @@ TEST(CoreString, Strndup)
     STRCMP_EQUAL(str, "");
     free (str);
 
+    str = string_strndup (str_test, 1);
+    CHECK(str);
+    CHECK(str != str_test);
+    STRCMP_EQUAL(str, "t");
+    free (str);
+
     str = string_strndup (str_test, 2);
     CHECK(str);
     CHECK(str != str_test);
     STRCMP_EQUAL(str, "te");
     free (str);
 
+    str = string_strndup (str_test, 3);
+    CHECK(str);
+    CHECK(str != str_test);
+    STRCMP_EQUAL(str, "tes");
+    free (str);
+
+    str = string_strndup (str_test, 4);
+    CHECK(str);
+    CHECK(str != str_test);
+    STRCMP_EQUAL(str, "test");
+    free (str);
+
+    str = string_strndup (str_test, 5);
+    CHECK(str);
+    CHECK(str != str_test);
+    STRCMP_EQUAL(str, "test");
+    free (str);
+
     str = string_strndup (str_test, 500);
     CHECK(str);
     CHECK(str != str_test);