diff --git a/arraylist.c b/arraylist.c
index 1789ad2..0d01069 100644
--- a/arraylist.c
+++ b/arraylist.c
@@ -22,6 +22,14 @@
 # include <strings.h>
 #endif /* HAVE_STRINGS_H */
 
+#if SIZEOF_SIZE_T == SIZEOF_INT
+#define SIZE_T_MAX UINT_MAX
+#elif SIZEOF_SIZE_T == SIZEOF_LONG
+#define SIZE_T_MAX ULONG_MAX
+#else
+#error Unable to determine size of size_t
+#endif
+
 #include "arraylist.h"
 
 struct array_list*
@@ -44,7 +52,7 @@ 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);
@@ -52,20 +60,20 @@ 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 */
-  if( arr->size >= INT_MAX / 2 )
+  /* Avoid undefined behaviour on size_t overflow */
+  if( arr->size >= SIZE_T_MAX / 2 )
     new_size = max;
   else
   {
@@ -73,8 +81,8 @@ static int array_list_expand_internal(struct array_list *arr, int max)
     if (new_size < max)
       new_size = max;
   }
-  if((size_t)new_size > (~((size_t)0)) / sizeof(void*)) return -1;
-  if(!(t = realloc(arr->array, ((size_t)new_size)*sizeof(void*)))) return -1;
+  if (new_size > (~((size_t)0)) / sizeof(void*)) return -1;
+  if (!(t = realloc(arr->array, new_size*sizeof(void*)))) return -1;
   arr->array = (void**)t;
   (void)memset(arr->array + arr->size, 0, (new_size-arr->size)*sizeof(void*));
   arr->size = new_size;
@@ -82,9 +90,9 @@ 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 (idx > SIZE_T_MAX - 1 ) return -1;
   if(array_list_expand_internal(arr, idx+1)) return -1;
   if(arr->array[idx]) arr->free_fn(arr->array[idx]);
   arr->array[idx] = data;
@@ -111,16 +119,16 @@ 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;
 }
 
 int
-array_list_del_idx( struct array_list *arr, int idx, int count )
+array_list_del_idx( struct array_list *arr, size_t idx, size_t count )
 {
-	int i, stop;
+	size_t i, stop;
 
 	stop = idx + count;
 	if ( idx >= arr->length || stop > arr->length ) return -1;
diff --git a/arraylist.h b/arraylist.h
index 9d2db5b..bc10903 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
@@ -54,7 +54,7 @@ extern void* array_list_bsearch(const void **key,
 		int (*sort_fn)(const void *, const void *));
 
 extern int 
-array_list_del_idx(struct array_list *arr, int i, int count);
+array_list_del_idx(struct array_list *arr, size_t idx, size_t count);
 
 #ifdef __cplusplus
 }
diff --git a/autoconf-archive/README.txt b/autoconf-archive/README.txt
index de65ae3..936582a 100644
--- a/autoconf-archive/README.txt
+++ b/autoconf-archive/README.txt
@@ -3,5 +3,6 @@ Autoconf Archive fetched from:
 
 http://gnu.mirror.iweb.com/autoconf-archive/autoconf-archive-2015.09.25.tar.xz
 
-Grabbed the minimum files needed for the AX_APPEND_COMPILE_FLAGS macro.
+Grabbed the minimum files needed for the AX_APPEND_COMPILE_FLAGS and
+AX_COMPILE_CHECK_SIZEOF macros.
 
diff --git a/autoconf-archive/m4/ax_compile_check_sizeof.m4 b/autoconf-archive/m4/ax_compile_check_sizeof.m4
new file mode 100644
index 0000000..00d0bcc
--- /dev/null
+++ b/autoconf-archive/m4/ax_compile_check_sizeof.m4
@@ -0,0 +1,114 @@
+# ===========================================================================
+#  http://www.gnu.org/software/autoconf-archive/ax_compile_check_sizeof.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_COMPILE_CHECK_SIZEOF(TYPE [, HEADERS [, EXTRA_SIZES...]])
+#
+# DESCRIPTION
+#
+#   This macro checks for the size of TYPE using compile checks, not run
+#   checks. You can supply extra HEADERS to look into. the check will cycle
+#   through 1 2 4 8 16 and any EXTRA_SIZES the user supplies. If a match is
+#   found, it will #define SIZEOF_`TYPE' to that value. Otherwise it will
+#   emit a configure time error indicating the size of the type could not be
+#   determined.
+#
+#   The trick is that C will not allow duplicate case labels. While this is
+#   valid C code:
+#
+#     switch (0) case 0: case 1:;
+#
+#   The following is not:
+#
+#     switch (0) case 0: case 0:;
+#
+#   Thus, the AC_TRY_COMPILE will fail if the currently tried size does not
+#   match.
+#
+#   Here is an example skeleton configure.in script, demonstrating the
+#   macro's usage:
+#
+#     AC_PROG_CC
+#     AC_CHECK_HEADERS(stddef.h unistd.h)
+#     AC_TYPE_SIZE_T
+#     AC_CHECK_TYPE(ssize_t, int)
+#
+#     headers='#ifdef HAVE_STDDEF_H
+#     #include <stddef.h>
+#     #endif
+#     #ifdef HAVE_UNISTD_H
+#     #include <unistd.h>
+#     #endif
+#     '
+#
+#     AX_COMPILE_CHECK_SIZEOF(char)
+#     AX_COMPILE_CHECK_SIZEOF(short)
+#     AX_COMPILE_CHECK_SIZEOF(int)
+#     AX_COMPILE_CHECK_SIZEOF(long)
+#     AX_COMPILE_CHECK_SIZEOF(unsigned char *)
+#     AX_COMPILE_CHECK_SIZEOF(void *)
+#     AX_COMPILE_CHECK_SIZEOF(size_t, $headers)
+#     AX_COMPILE_CHECK_SIZEOF(ssize_t, $headers)
+#     AX_COMPILE_CHECK_SIZEOF(ptrdiff_t, $headers)
+#     AX_COMPILE_CHECK_SIZEOF(off_t, $headers)
+#
+# LICENSE
+#
+#   Copyright (c) 2008 Kaveh Ghazi <ghazi@caip.rutgers.edu>
+#
+#   This program is free software: you can redistribute it and/or modify it
+#   under the terms of the GNU General Public License as published by the
+#   Free Software Foundation, either version 3 of the License, or (at your
+#   option) any later version.
+#
+#   This program is distributed in the hope that it will be useful, but
+#   WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+#   Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License along
+#   with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+#   As a special exception, the respective Autoconf Macro's copyright owner
+#   gives unlimited permission to copy, distribute and modify the configure
+#   scripts that are the output of Autoconf when processing the Macro. You
+#   need not follow the terms of the GNU General Public License when using
+#   or distributing such scripts, even though portions of the text of the
+#   Macro appear in them. The GNU General Public License (GPL) does govern
+#   all other use of the material that constitutes the Autoconf Macro.
+#
+#   This special exception to the GPL applies to versions of the Autoconf
+#   Macro released by the Autoconf Archive. When you make and distribute a
+#   modified version of the Autoconf Macro, you may extend this special
+#   exception to the GPL to apply to your modified version as well.
+
+#serial 5
+
+AU_ALIAS([AC_COMPILE_CHECK_SIZEOF], [AX_COMPILE_CHECK_SIZEOF])
+AC_DEFUN([AX_COMPILE_CHECK_SIZEOF],
+[changequote(<<, >>)dnl
+dnl The name to #define.
+define(<<AC_TYPE_NAME>>, translit(sizeof_$1, [a-z *], [A-Z_P]))dnl
+dnl The cache variable name.
+define(<<AC_CV_NAME>>, translit(ac_cv_sizeof_$1, [ *], [_p]))dnl
+changequote([, ])dnl
+AC_MSG_CHECKING(size of $1)
+AC_CACHE_VAL(AC_CV_NAME,
+[for ac_size in 4 8 1 2 16 $3 ; do # List sizes in rough order of prevalence.
+  AC_TRY_COMPILE([#include "confdefs.h"
+#include <sys/types.h>
+$2
+], [switch (0) case 0: case (sizeof ($1) == $ac_size):;], AC_CV_NAME=$ac_size)
+  if test x$AC_CV_NAME != x ; then break; fi
+done
+])
+if test x$AC_CV_NAME = x ; then
+  AC_MSG_ERROR([cannot determine a size for $1])
+fi
+AC_MSG_RESULT($AC_CV_NAME)
+AC_DEFINE_UNQUOTED(AC_TYPE_NAME, $AC_CV_NAME, [The number of bytes in type $1])
+undefine([AC_TYPE_NAME])dnl
+undefine([AC_CV_NAME])dnl
+])
diff --git a/configure.ac b/configure.ac
index ed86210..631464d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -107,6 +107,10 @@ AX_APPEND_COMPILE_FLAGS([-Wall -Werror -Wno-error=deprecated-declarations])
 AX_APPEND_COMPILE_FLAGS([-Wextra -Wwrite-string -Wno-unused-parameter])
 AX_APPEND_COMPILE_FLAGS([-D_GNU_SOURCE -D_REENTRANT])
 
+AX_COMPILE_CHECK_SIZEOF(int)
+AX_COMPILE_CHECK_SIZEOF(long)
+AX_COMPILE_CHECK_SIZEOF(size_t, [#include "json_inttypes.h"])
+
 AC_CONFIG_FILES([
 Makefile
 json-c.pc
diff --git a/json_object.c b/json_object.c
index 46701e7..f0d1251 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);
 }
@@ -1000,7 +1000,7 @@ struct json_object* json_object_array_get_idx(const struct json_object *jso,
 static int json_array_equal(struct json_object* jso1,
 			    struct json_object* jso2)
 {
-	int len, i;
+	size_t len, i;
 
 	len = json_object_array_length(jso1);
 	if (len != json_object_array_length(jso2))
@@ -1079,7 +1079,7 @@ int json_object_equal(struct json_object* jso1, struct json_object* jso2)
 	return 0;
 }
 
-int json_object_array_del_idx(struct json_object *jso, int idx, int count)
+int json_object_array_del_idx(struct json_object *jso, size_t idx, size_t count)
 {
 	return array_list_del_idx(jso->o.c_array, idx, count);
 }
diff --git a/json_object.h b/json_object.h
index a89de44..669f8d2 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)
  *
@@ -537,7 +537,7 @@ extern struct json_object* json_object_array_get_idx(const struct json_object *o
  * @param count the number of elements to delete
  * @returns 0 if the elements were successfully deleted
  */
-extern int json_object_array_del_idx(struct json_object *obj, int idx, int count);
+extern int json_object_array_del_idx(struct json_object *obj, size_t idx, size_t count);
 
 /* json_bool type methods */
 
diff --git a/tests/test1.c b/tests/test1.c
index 2446a10..3d5b09a 100644
--- a/tests/test1.c
+++ b/tests/test1.c
@@ -53,8 +53,8 @@ void test_array_del_idx(void);
 void test_array_del_idx()
 {
 	int rc;
-	int ii;
-	int orig_array_len;
+	size_t ii;
+	size_t orig_array_len;
 	json_object *my_array;
 #ifdef TEST_FORMATTED
 	int sflags = 0;
@@ -105,7 +105,7 @@ void test_array_del_idx()
 int main(int argc, char **argv)
 {
 	json_object *my_string, *my_int, *my_object, *my_array;
-	int i;
+	size_t i;
 #ifdef TEST_FORMATTED
 	int sflags = 0;
 #endif