diff --git a/magick/cache.c b/magick/cache.c
index 3a7c08d..33fdb60 100644
--- a/magick/cache.c
+++ b/magick/cache.c
@@ -4217,10 +4217,10 @@
MaxTextExtent);
cache_info->type=DiskCache;
cache_info->offset=(*offset);
- if (OpenPixelCache(image,IOMode,exception) == MagickFalse)
+ if (OpenPixelCache(image,ReadMode,exception) == MagickFalse)
return(MagickFalse);
*offset+=cache_info->length+page_size-(cache_info->length % page_size);
- return(MagickTrue);
+ return(SetImageExtent(image,0,0));
}
if ((cache_info->mode != ReadMode) && (cache_info->type != MemoryCache) &&
(cache_info->reference_count == 1))