diff --git a/json_object.c b/json_object.c
index b48b889..3a5d860 100644
--- a/json_object.c
+++ b/json_object.c
@@ -574,13 +574,13 @@ int json_object_object_add_ex(struct json_object *jso, const char *const key,
 	return json_object_object_add_ex_len(jso, key, strlen(key), val, opts);
 }
 
-int json_object_object_add_ex_len(struct json_object *jso, const char *const key, const int len,
+int json_object_object_add_ex_len(struct json_object *jso, const char *const key, const size_t len,
                                   struct json_object *const val, const unsigned opts)
 {
 	// Created on the stack rather than calling `json_key_new_ptr`
 	// or `json_key_new_imm` since this saves copying `key` if it turns
 	// out the value already exists in the hash table
-	const struct json_key hashable = {.length = len, .str = {.pdata = key}};
+	struct json_key hashable = {len, {key}};
 	return json_object_object_add_key(jso, &hashable, val, opts);
 }
 
@@ -646,7 +646,7 @@ int json_object_object_add(struct json_object *jso, const char *key, struct json
 	return json_object_object_add_ex_len(jso, key, strlen(key), val, 0);
 }
 
-int json_object_object_add_len(struct json_object *jso, const char *key, const int len,
+int json_object_object_add_len(struct json_object *jso, const char *key, const size_t len,
                                struct json_object *val)
 {
 	return json_object_object_add_ex_len(jso, key, len, val, 0);
@@ -671,7 +671,7 @@ struct json_object *json_object_object_get(const struct json_object *jso, const
 }
 
 struct json_object *json_object_object_get_len(const struct json_object *jso, const char *key,
-                                               const int len)
+                                               const size_t len)
 {
 	struct json_object *result = NULL;
 	json_object_object_get_ex_len(jso, key, len, &result);
@@ -685,7 +685,7 @@ json_bool json_object_object_get_ex(const struct json_object *jso, const char *k
 }
 
 json_bool json_object_object_get_ex_len(const struct json_object *jso, const char *key,
-                                        const int len, struct json_object **value)
+                                        const size_t len, struct json_object **value)
 {
 	if (value != NULL)
 		*value = NULL;
@@ -697,7 +697,7 @@ json_bool json_object_object_get_ex_len(const struct json_object *jso, const cha
 	{
 	case json_type_object:
 	{
-		const struct json_key hashable = {.length = len, .str = {.pdata = key}};
+		const struct json_key hashable = {len, {key}};
 		return json_object_object_get_key(jso, &hashable, value);
 	}
 	default:
@@ -719,9 +719,9 @@ void json_object_object_del(struct json_object *jso, const char *key)
 	json_object_object_del_len(jso, key, strlen(key));
 }
 
-void json_object_object_del_len(struct json_object *jso, const char *key, const int len)
+void json_object_object_del_len(struct json_object *jso, const char *key, const size_t len)
 {
-	const struct json_key hashable = {.length = len, .str = {.pdata = key}};
+	const struct json_key hashable = {len, {key}};
 	json_object_object_del_key(jso, &hashable);
 }
 
@@ -1888,7 +1888,7 @@ struct json_key *json_key_new_ptr(const size_t length, const char *data)
 	{
 		return NULL;
 	}
-	result->length = length;
+	result->length = (ssize_t)length;
 	result->str.pdata = data;
 	return result;
 }
@@ -1907,9 +1907,8 @@ struct json_key *json_key_new_imm(const size_t length, const char *data)
 	{
 		return NULL;
 	}
-	result->length = -length;
-	char *unconst = _LH_UNCONST(result->str.idata);
-	memcpy(unconst, data, length);
-	unconst[length] = '\0';
+	result->length = -((ssize_t)length);
+	memcpy(result->str.idata, data, length);
+	result->str.idata[length] = '\0';
 	return result;
 }
diff --git a/json_object.h b/json_object.h
index 771ea73..70ebcef 100644
--- a/json_object.h
+++ b/json_object.h
@@ -357,7 +357,8 @@ JSON_EXPORT int json_object_object_length(const struct json_object *obj);
  */
 JSON_C_CONST_FUNCTION(JSON_EXPORT size_t json_c_object_sizeof(void));
 
-/** Add an object field to a json_object of type json_type_object
+/**
+ * @brief Add an object field to a json_object of type json_type_object
  *
  * The reference count of `val` will *not* be incremented, in effect
  * transferring ownership that object to `obj`, and thus `val` will be
@@ -385,7 +386,8 @@ JSON_C_CONST_FUNCTION(JSON_EXPORT size_t json_c_object_sizeof(void));
 JSON_EXPORT int json_object_object_add(struct json_object *obj, const char *key,
                                        struct json_object *val);
 
-/** Add an object field to a json_object of type json_type_object
+/**
+ * @brief Add an object field to a json_object of type json_type_object
  *
  * The reference count of `val` will *not* be incremented, in effect
  * transferring ownership that object to `obj`, and thus `val` will be
@@ -412,10 +414,11 @@ JSON_EXPORT int json_object_object_add(struct json_object *obj, const char *key,
  * @return On success, @c 0 is returned.
  * 	On error, a negative value is returned.
  */
-JSON_EXPORT int json_object_object_add_len(struct json_object *obj, const char *key, const int len,
-                                           struct json_object *val);
+JSON_EXPORT int json_object_object_add_len(struct json_object *obj, const char *key,
+                                           const size_t len, struct json_object *val);
 
-/** Add an object field to a json_object of type json_type_object
+/**
+ * @brief Add an object field to a json_object of type json_type_object
  *
  * The semantics are identical to json_object_object_add, except that an
  * additional flag fields gives you more control over some detail aspects
@@ -434,7 +437,8 @@ JSON_EXPORT int json_object_object_add_len(struct json_object *obj, const char *
 JSON_EXPORT int json_object_object_add_ex(struct json_object *obj, const char *const key,
                                           struct json_object *const val, const unsigned opts);
 
-/** Add an object field to a json_object of type json_type_object
+/**
+ * @brief Add an object field to a json_object of type json_type_object
  *
  * The semantics are identical to json_object_object_add, except that an
  * additional flag fields gives you more control over some detail aspects
@@ -453,7 +457,7 @@ JSON_EXPORT int json_object_object_add_ex(struct json_object *obj, const char *c
  * 	On error, a negative value is returned.
  */
 JSON_EXPORT int json_object_object_add_ex_len(struct json_object *obj, const char *const key,
-                                              const int len, struct json_object *const val,
+                                              const size_t len, struct json_object *const val,
                                               const unsigned opts);
 
 /**
@@ -515,7 +519,7 @@ JSON_EXPORT struct json_object *json_object_object_get(const struct json_object
  */
 
 JSON_EXPORT struct json_object *json_object_object_get_len(const struct json_object *obj,
-                                                           const char *key, const int len);
+                                                           const char *key, const size_t len);
 
 /**
  * @brief Get the json_object associated with a given object field.
@@ -557,7 +561,7 @@ JSON_EXPORT json_bool json_object_object_get_ex(const struct json_object *obj, c
  * @returns whether or not the key exists
  */
 JSON_EXPORT json_bool json_object_object_get_ex_len(const struct json_object *obj, const char *key,
-                                                    const int len, struct json_object **value);
+                                                    const size_t len, struct json_object **value);
 
 /**
  * @brief Get the json_object associated with a given object field.
@@ -605,7 +609,7 @@ JSON_EXPORT void json_object_object_del(struct json_object *obj, const char *key
  * @param len the length of @p key
  */
 JSON_EXPORT void json_object_object_del_len(struct json_object *jso, const char *key,
-                                            const int len);
+                                            const size_t len);
 
 /**
  * @brief Delete the given json_object field
@@ -617,8 +621,7 @@ JSON_EXPORT void json_object_object_del_len(struct json_object *jso, const char
  * @param obj the json_object instance
  * @param key the object field name
  */
-JSON_EXPORT int json_object_object_del_key(struct json_object *jso_base,
-                                           const struct json_key *key);
+JSON_EXPORT int json_object_object_del_key(struct json_object *obj, const struct json_key *key);
 
 /**
  * @brief Iterate through all keys and values of an object.
@@ -655,12 +658,12 @@ JSON_EXPORT int json_object_object_del_key(struct json_object *jso_base,
 #else /* ANSI C or MSC */
 
 #define json_object_object_foreach(obj, key, val)                              \
-	char *key = NULL;                                                      \
+	struct json_key *key = NULL;                                           \
 	struct json_object *val = NULL;                                        \
 	struct lh_entry *entry##key;                                           \
 	struct lh_entry *entry_next##key = NULL;                               \
 	for (entry##key = json_object_get_object(obj)->head;                   \
-	     (entry##key ? (key = (char *)lh_entry_k(entry##key),              \
+	     (entry##key ? (key = (struct json_key *)lh_entry_k(entry##key),   \
 	                   val = (struct json_object *)lh_entry_v(entry##key), \
 	                   entry_next##key = entry##key->next, entry##key)     \
 	                 : 0);                                                 \
diff --git a/json_object_private.h b/json_object_private.h
index 6ad1044..cae49f7 100644
--- a/json_object_private.h
+++ b/json_object_private.h
@@ -141,7 +141,7 @@ struct json_key
 		 * enough space to store the whole string (of length `len`)
 		 * and one additional null character.
 		 */
-		const char idata[0];
+		char idata[0];
 	} str;
 };