diff --git a/tests/test1.c b/tests/test1.c
index 4d29601..aa156f3 100644
--- a/tests/test1.c
+++ b/tests/test1.c
@@ -306,7 +306,9 @@ int main(int argc, char **argv)
 	printf("my_object=\n");
 	json_object_object_foreach(my_object, key, val)
 	{
-		printf("\t%s: %s\n", key, json_object_to_json_string(val));
+		putchar('\t');
+		lh_string_print(key, stdout);
+		printf(": %s\n", json_object_to_json_string(val));
 	}
 	printf("my_object.to_string()=%s\n", json_object_to_json_string(my_object));
 
diff --git a/tests/testReplaceExisting.c b/tests/testReplaceExisting.c
index ee3cae0..5d99212 100644
--- a/tests/testReplaceExisting.c
+++ b/tests/testReplaceExisting.c
@@ -24,10 +24,11 @@ int main(int argc, char **argv)
 	int orig_count = 0;
 	json_object_object_foreach(my_object, key0, val0)
 	{
-		printf("Key at index %d is [%s] %d", orig_count, key0, (val0 == NULL));
-		if (strcmp(key0, "deleteme") == 0)
+		printf("Key at index %d is [%s] %d", orig_count, lh_string_data(key0),
+		       (val0 == NULL));
+		if (strcmp(lh_string_data(key0), "deleteme") == 0)
 		{
-			json_object_object_del(my_object, key0);
+			json_object_object_del(my_object, lh_string_data(key0));
 			printf(" (deleted)\n");
 		}
 		else
@@ -37,17 +38,19 @@ int main(int argc, char **argv)
 
 	printf("==== replace-value first loop starting ====\n");
 
-	const char *original_key = NULL;
+	const struct lh_string *original_key = NULL;
 	orig_count = 0;
 	json_object_object_foreach(my_object, key, val)
 	{
-		printf("Key at index %d is [%s] %d\n", orig_count, key, (val == NULL));
+		printf("Key at index %d is [%s] %d\n", orig_count, lh_string_data(key),
+		       (val == NULL));
 		orig_count++;
-		if (strcmp(key, "foo2") != 0)
+		if (strcmp(lh_string_data(key), "foo2") != 0)
 			continue;
-		printf("replacing value for key [%s]\n", key);
+		printf("replacing value for key [%s]\n", lh_string_data(key));
 		original_key = key;
-		json_object_object_add(my_object, key, json_object_new_string("zzz"));
+		json_object_object_add(my_object, lh_string_data(key0),
+		                       json_object_new_string("zzz"));
 	}
 
 	printf("==== second loop starting ====\n");
@@ -56,11 +59,12 @@ int main(int argc, char **argv)
 	int retval = 0;
 	json_object_object_foreach(my_object, key2, val2)
 	{
-		printf("Key at index %d is [%s] %d\n", new_count, key2, (val2 == NULL));
+		printf("Key at index %d is [%s] %d\n", new_count, lh_string_data(key2),
+		       (val2 == NULL));
 		new_count++;
-		if (strcmp(key2, "foo2") != 0)
+		if (strcmp(lh_string_data(key2), "foo2") != 0)
 			continue;
-		printf("pointer for key [%s] does %smatch\n", key2,
+		printf("pointer for key [%s] does %smatch\n", lh_string_data(key2),
 		       (key2 == original_key) ? "" : "NOT ");
 		if (key2 != original_key)
 			retval = 1;
diff --git a/tests/test_deep_copy.c b/tests/test_deep_copy.c
index 34ef1fe..b1c685e 100644
--- a/tests/test_deep_copy.c
+++ b/tests/test_deep_copy.c
@@ -93,14 +93,14 @@ int my_custom_serializer(struct json_object *jso, struct printbuf *pb, int level
 }
 
 json_c_shallow_copy_fn my_shallow_copy;
-int my_shallow_copy(json_object *src, json_object *parent, const char *key, size_t index,
-                    json_object **dst)
+int my_shallow_copy(json_object *src, json_object *parent, const struct lh_string *key,
+                    size_t index, json_object **dst)
 {
 	int rc;
 	rc = json_c_shallow_copy_default(src, parent, key, index, dst);
 	if (rc < 0)
 		return rc;
-	if (key != NULL && strcmp(key, "with_serializer") == 0)
+	if (key != NULL && strcmp(lh_string_data(key), "with_serializer") == 0)
 	{
 		printf("CALLED: my_shallow_copy on with_serializer object\n");
 		void *userdata = json_object_get_userdata(src);
diff --git a/tests/test_null_keys_add.c b/tests/test_null_keys_add.c
index ce31582..a2965cd 100644
--- a/tests/test_null_keys_add.c
+++ b/tests/test_null_keys_add.c
@@ -9,6 +9,7 @@
 #include "json_inttypes.h"
 #include "json_object.h"
 #include "json_tokener.h"
+#include "linkhash.h"
 
 int main(void)
 {
@@ -65,10 +66,33 @@ int main(void)
 		return 1;
 	}
 
+	// Check the previous keys are still the same present
+	struct json_object *foo = json_object_object_get(parsed, foo_key);
+	if (!json_object_is_type(foo, json_type_double))
+	{
+		printf("Key \"%s\" should be `json_type_double` (%d) but was %d (error!)\n",
+		       foo_key, (int)json_type_double, json_object_get_type(foo));
+		return 1;
+	}
+	else
+	{
+		printf("Key \"%s\" parsed as right type\n", foo_key);
+	}
+	struct json_object *bar = json_object_object_get(parsed, bar_key);
+	if (!json_object_is_type(bar, json_type_array))
+	{
+		printf("Key \"%s\" should be `json_type_array` (%d) but was %d (error!)\n", bar_key,
+		       (int)json_type_array, json_object_get_type(bar));
+		return 1;
+	}
+	else
+	{
+		printf("Key \"%s\" parsed as right type\n", bar_key);
+	}
+
 	// Add the new key
 	struct json_object *new_str = json_object_new_string_len(toadd_value, toadd_value_len);
-	if (json_object_object_add_ex(parsed, toadd_key, new_str,
-	                              JSON_C_OBJECT_ADD_KEY_IS_NEW |
+	if (json_object_object_add_ex_len(parsed, toadd_key, toadd_key_len, new_str,
 	                                  JSON_C_OBJECT_KEY_IS_CONSTANT) != 0)
 	{
 		printf("An error occured adding the key \"%s\" (error!)\n", toadd_key_printable);
@@ -86,6 +110,13 @@ int main(void)
 	{
 		printf("Have three keys, but don't have the right value in \"%s\" (error!)\n",
 		       toadd_key_printable);
+		printf("Keys :\n");
+		json_object_object_foreach(parsed, key, val)
+		{
+			putchar('\"');
+			fwrite(lh_string_data(key), lh_string_size(key), 1, stdout);
+			printf("\" (%zd)\n", lh_string_size(key));
+		}
 		return 1;
 	}
 	else
@@ -94,7 +125,7 @@ int main(void)
 	}
 
 	// Check the previous keys are still the same present
-	struct json_object *foo = json_object_object_get(parsed, foo_key);
+	foo = json_object_object_get(parsed, foo_key);
 	if (!json_object_is_type(foo, json_type_double))
 	{
 		printf("Key \"%s\" should be `json_type_double` (%d) but was %d (error!)\n",
@@ -105,11 +136,11 @@ int main(void)
 	{
 		printf("Key \"%s\" is still the same\n", foo_key);
 	}
-	struct json_object *bar = json_object_object_get(parsed, bar_key);
-	if (!json_object_is_type(foo, json_type_array))
+	bar = json_object_object_get(parsed, bar_key);
+	if (!json_object_is_type(bar, json_type_array))
 	{
 		printf("Key \"%s\" should be `json_type_array` (%d) but was %d (error!)\n", bar_key,
-		       (int)json_type_array, json_object_get_type(foo));
+		       (int)json_type_array, json_object_get_type(bar));
 		return 1;
 	}
 	else
diff --git a/tests/test_null_keys_add.expected b/tests/test_null_keys_add.expected
index 5e9a9c1..621a6df 100644
--- a/tests/test_null_keys_add.expected
+++ b/tests/test_null_keys_add.expected
@@ -1,5 +1,7 @@
 Parsed input: { "foo": 14.5, "bar": [] }
 Result is `json_type_object`
+Key "foo" parsed as right type
+Key "bar" parsed as right type
 Added the key "foo\0bar" successfully
 Key "foo" is still the same
 Key "bar" is still the same
diff --git a/tests/test_object_iterator.c b/tests/test_object_iterator.c
index da5192a..9e0a178 100644
--- a/tests/test_object_iterator.c
+++ b/tests/test_object_iterator.c
@@ -6,6 +6,7 @@
 #include "json_object.h"
 #include "json_object_iterator.h"
 #include "json_tokener.h"
+#include "linkhash.h"
 
 int main(int atgc, char **argv)
 {
@@ -30,7 +31,7 @@ int main(int atgc, char **argv)
 
 	while (!json_object_iter_equal(&it, &itEnd))
 	{
-		printf("%s\n", json_object_iter_peek_name(&it));
+		printf("%s\n", lh_string_data(json_object_iter_peek_name(&it)));
 		printf("%s\n", json_object_to_json_string(json_object_iter_peek_value(&it)));
 		json_object_iter_next(&it);
 	}
diff --git a/tests/test_parse.c b/tests/test_parse.c
index 5363f32..19238c4 100644
--- a/tests/test_parse.c
+++ b/tests/test_parse.c
@@ -215,7 +215,7 @@ static void do_clear_serializer(json_object *jso)
 }
 
 static int clear_serializer(json_object *jso, int flags, json_object *parent_jso,
-                            const char *jso_key, size_t *jso_index, void *userarg)
+                            const struct lh_string *jso_key, size_t *jso_index, void *userarg)
 {
 	if (jso)
 		json_object_set_serializer(jso, NULL, NULL, NULL);
diff --git a/tests/test_visit.c b/tests/test_visit.c
index eee469e..b226d87 100644
--- a/tests/test_visit.c
+++ b/tests/test_visit.c
@@ -68,17 +68,17 @@ int main(void)
 	return 0;
 }
 
-static int emit_object(json_object *jso, int flags, json_object *parent_jso, const char *jso_key,
-                       size_t *jso_index, void *userarg)
+static int emit_object(json_object *jso, int flags, json_object *parent_jso,
+                       const struct lh_string *jso_key, size_t *jso_index, void *userarg)
 {
 	printf("flags: 0x%x, key: %s, index: %ld, value: %s\n", flags,
-	       (jso_key ? jso_key : "(null)"), (jso_index ? (long)*jso_index : -1L),
+	       (jso_key ? lh_string_data(jso_key) : "(null)"), (jso_index ? (long)*jso_index : -1L),
 	       json_object_to_json_string(jso));
 	return JSON_C_VISIT_RETURN_CONTINUE;
 }
 
-static int skip_arrays(json_object *jso, int flags, json_object *parent_jso, const char *jso_key,
-                       size_t *jso_index, void *userarg)
+static int skip_arrays(json_object *jso, int flags, json_object *parent_jso,
+                       const struct lh_string *jso_key, size_t *jso_index, void *userarg)
 {
 	(void)emit_object(jso, flags, parent_jso, jso_key, jso_index, userarg);
 	if (json_object_get_type(jso) == json_type_array)
@@ -86,16 +86,16 @@ static int skip_arrays(json_object *jso, int flags, json_object *parent_jso, con
 	return JSON_C_VISIT_RETURN_CONTINUE;
 }
 
-static int pop_and_stop(json_object *jso, int flags, json_object *parent_jso, const char *jso_key,
-                        size_t *jso_index, void *userarg)
+static int pop_and_stop(json_object *jso, int flags, json_object *parent_jso,
+                        const struct lh_string *jso_key, size_t *jso_index, void *userarg)
 {
 	(void)emit_object(jso, flags, parent_jso, jso_key, jso_index, userarg);
-	if (jso_key != NULL && strcmp(jso_key, "subobj1") == 0)
+	if (jso_key != NULL && strcmp(lh_string_data(jso_key), "subobj1") == 0)
 	{
 		printf("POP after handling subobj1\n");
 		return JSON_C_VISIT_RETURN_POP;
 	}
-	if (jso_key != NULL && strcmp(jso_key, "obj3") == 0)
+	if (jso_key != NULL && strcmp(lh_string_data(jso_key), "obj3") == 0)
 	{
 		printf("STOP after handling obj3\n");
 		return JSON_C_VISIT_RETURN_STOP;
@@ -103,11 +103,11 @@ static int pop_and_stop(json_object *jso, int flags, json_object *parent_jso, co
 	return JSON_C_VISIT_RETURN_CONTINUE;
 }
 
-static int err_on_subobj2(json_object *jso, int flags, json_object *parent_jso, const char *jso_key,
-                          size_t *jso_index, void *userarg)
+static int err_on_subobj2(json_object *jso, int flags, json_object *parent_jso,
+                          const struct lh_string *jso_key, size_t *jso_index, void *userarg)
 {
 	(void)emit_object(jso, flags, parent_jso, jso_key, jso_index, userarg);
-	if (jso_key != NULL && strcmp(jso_key, "subobj2") == 0)
+	if (jso_key != NULL && strcmp(lh_string_data(jso_key), "subobj2") == 0)
 	{
 		printf("ERROR after handling subobj1\n");
 		return JSON_C_VISIT_RETURN_ERROR;
@@ -115,8 +115,8 @@ static int err_on_subobj2(json_object *jso, int flags, json_object *parent_jso,
 	return JSON_C_VISIT_RETURN_CONTINUE;
 }
 
-static int pop_array(json_object *jso, int flags, json_object *parent_jso, const char *jso_key,
-                     size_t *jso_index, void *userarg)
+static int pop_array(json_object *jso, int flags, json_object *parent_jso,
+                     const struct lh_string *jso_key, size_t *jso_index, void *userarg)
 {
 	(void)emit_object(jso, flags, parent_jso, jso_key, jso_index, userarg);
 	if (jso_index != NULL && (*jso_index == 0))
@@ -127,8 +127,8 @@ static int pop_array(json_object *jso, int flags, json_object *parent_jso, const
 	return JSON_C_VISIT_RETURN_CONTINUE;
 }
 
-static int stop_array(json_object *jso, int flags, json_object *parent_jso, const char *jso_key,
-                      size_t *jso_index, void *userarg)
+static int stop_array(json_object *jso, int flags, json_object *parent_jso,
+                      const struct lh_string *jso_key, size_t *jso_index, void *userarg)
 {
 	(void)emit_object(jso, flags, parent_jso, jso_key, jso_index, userarg);
 	if (jso_index != NULL && (*jso_index == 0))
@@ -139,11 +139,11 @@ static int stop_array(json_object *jso, int flags, json_object *parent_jso, cons
 	return JSON_C_VISIT_RETURN_CONTINUE;
 }
 
-static int err_return(json_object *jso, int flags, json_object *parent_jso, const char *jso_key,
-                      size_t *jso_index, void *userarg)
+static int err_return(json_object *jso, int flags, json_object *parent_jso,
+                      const struct lh_string *jso_key, size_t *jso_index, void *userarg)
 {
 	printf("flags: 0x%x, key: %s, index: %ld, value: %s\n", flags,
-	       (jso_key ? jso_key : "(null)"), (jso_index ? (long)*jso_index : -1L),
+	       (jso_key ? lh_string_data(jso_key) : "(null)"), (jso_index ? (long)*jso_index : -1L),
 	       json_object_to_json_string(jso));
 	return 100;
 }