diff --git a/magick/configure.h b/magick/configure.h
index 98805d5..5b431ab 100644
--- a/magick/configure.h
+++ b/magick/configure.h
@@ -39,12 +39,12 @@
*previous,
*next; /* deprecated, use GetConfigureInfoList() */
- unsigned long
+ size_t
signature;
} ConfigureInfo;
extern MagickExport char
- **GetConfigureList(const char *,unsigned long *,ExceptionInfo *),
+ **GetConfigureList(const char *,size_t *,ExceptionInfo *),
*GetConfigureOption(const char *);
extern MagickExport const char
@@ -52,7 +52,7 @@
extern MagickExport const ConfigureInfo
*GetConfigureInfo(const char *,ExceptionInfo *),
- **GetConfigureInfoList(const char *,unsigned long *,ExceptionInfo *);
+ **GetConfigureInfoList(const char *,size_t *,ExceptionInfo *);
extern MagickExport LinkedListInfo
*DestroyConfigureOptions(LinkedListInfo *),
