diff --git a/arraylist.c b/arraylist.c
index 1789ad2..a02266e 100644
--- a/arraylist.c
+++ b/arraylist.c
@@ -44,7 +44,7 @@ array_list_new(array_list_free_fn *free_fn)
 extern void
 array_list_free(struct array_list *arr)
 {
-  int i;
+  size_t i;
   for(i = 0; i < arr->length; i++)
     if(arr->array[i]) arr->free_fn(arr->array[i]);
   free(arr->array);
@@ -52,16 +52,16 @@ array_list_free(struct array_list *arr)
 }
 
 void*
-array_list_get_idx(struct array_list *arr, int i)
+array_list_get_idx(struct array_list *arr, size_t i)
 {
   if(i >= arr->length) return NULL;
   return arr->array[i];
 }
 
-static int array_list_expand_internal(struct array_list *arr, int max)
+static int array_list_expand_internal(struct array_list *arr, size_t max)
 {
   void *t;
-  int new_size;
+  size_t new_size;
 
   if(max < arr->size) return 0;
   /* Avoid undefined behaviour on int32 overflow */
@@ -82,7 +82,7 @@ static int array_list_expand_internal(struct array_list *arr, int max)
 }
 
 int
-array_list_put_idx(struct array_list *arr, int idx, void *data)
+array_list_put_idx(struct array_list *arr, size_t idx, void *data)
 {
   if( idx < 0 || idx > INT_MAX - 1 ) return -1;
   if(array_list_expand_internal(arr, idx+1)) return -1;
@@ -111,7 +111,7 @@ void* array_list_bsearch(const void **key, struct array_list *arr,
 			sort_fn);
 }
 
-int
+size_t
 array_list_length(struct array_list *arr)
 {
   return arr->length;
diff --git a/arraylist.h b/arraylist.h
index 9d2db5b..bcbaa8b 100644
--- a/arraylist.h
+++ b/arraylist.h
@@ -23,8 +23,8 @@ typedef void (array_list_free_fn) (void *data);
 struct array_list
 {
   void **array;
-  int length;
-  int size;
+  size_t length;
+  size_t size;
   array_list_free_fn *free_fn;
 };
 
@@ -35,15 +35,15 @@ extern void
 array_list_free(struct array_list *al);
 
 extern void*
-array_list_get_idx(struct array_list *al, int i);
+array_list_get_idx(struct array_list *al, size_t i);
 
 extern int
-array_list_put_idx(struct array_list *al, int i, void *data);
+array_list_put_idx(struct array_list *al, size_t i, void *data);
 
 extern int
 array_list_add(struct array_list *al, void *data);
 
-extern int
+extern size_t
 array_list_length(struct array_list *al);
 
 extern void
diff --git a/json_object.c b/json_object.c
index 46701e7..b0b381e 100644
--- a/json_object.c
+++ b/json_object.c
@@ -879,7 +879,7 @@ static int json_object_array_to_json_string(struct json_object* jso,
                                             int flags)
 {
 	int had_children = 0;
-	int ii;
+	size_t ii;
 	sprintbuf(pb, "[");
 	if (flags & JSON_C_TO_STRING_PRETTY)
 		sprintbuf(pb, "\n");
@@ -975,7 +975,7 @@ struct json_object* json_object_array_bsearch(
 	return *result;
 }
 
-int json_object_array_length(const struct json_object *jso)
+size_t json_object_array_length(const struct json_object *jso)
 {
 	return array_list_length(jso->o.c_array);
 }
@@ -985,14 +985,14 @@ int json_object_array_add(struct json_object *jso,struct json_object *val)
 	return array_list_add(jso->o.c_array, val);
 }
 
-int json_object_array_put_idx(struct json_object *jso, int idx,
+int json_object_array_put_idx(struct json_object *jso, size_t idx,
 			      struct json_object *val)
 {
 	return array_list_put_idx(jso->o.c_array, idx, val);
 }
 
 struct json_object* json_object_array_get_idx(const struct json_object *jso,
-					      int idx)
+					      size_t idx)
 {
 	return (struct json_object*)array_list_get_idx(jso->o.c_array, idx);
 }
diff --git a/json_object.h b/json_object.h
index a89de44..46540b7 100644
--- a/json_object.h
+++ b/json_object.h
@@ -457,7 +457,7 @@ extern struct array_list* json_object_get_array(const struct json_object *obj);
  * @param obj the json_object instance
  * @returns an int
  */
-extern int json_object_array_length(const struct json_object *obj);
+extern size_t json_object_array_length(const struct json_object *obj);
 
 /** Sorts the elements of jso of type json_type_array
 *
@@ -515,7 +515,7 @@ extern int json_object_array_add(struct json_object *obj,
  * @param idx the index to insert the element at
  * @param val the json_object to be added
  */
-extern int json_object_array_put_idx(struct json_object *obj, int idx,
+extern int json_object_array_put_idx(struct json_object *obj, size_t idx,
 				     struct json_object *val);
 
 /** Get the element at specificed index of the array (a json_object of type json_type_array)
@@ -524,7 +524,7 @@ extern int json_object_array_put_idx(struct json_object *obj, int idx,
  * @returns the json_object at the specified index (or NULL)
  */
 extern struct json_object* json_object_array_get_idx(const struct json_object *obj,
-						     int idx);
+						     size_t idx);
 
 /** Delete an elements from a specified index in an array (a json_object of type json_type_array)
  *