diff --git a/magick/memory.c b/magick/memory.c
index c5becbdd0e..8721a2326c 100644
--- a/magick/memory.c
+++ b/magick/memory.c
@@ -1628,7 +1628,7 @@ MagickPrivate MagickBooleanType ShredMagickMemory(void *memory,
   /*
     Overwrite the memory buffer with random data.
   */
-  quantum=(size_t) MagickMin(length,MagickMaxBufferExtent);
+  quantum=(size_t) MagickMin(length,MagickMinBufferExtent);
   random_info=AcquireRandomInfo();
   key=GetRandomKey(random_info,quantum);
   for (i=0; i < passes; i++)
diff --git a/magick/utility.c b/magick/utility.c
index 16ccbf6398..3b31119001 100644
--- a/magick/utility.c
+++ b/magick/utility.c
@@ -1901,9 +1901,9 @@ MagickPrivate MagickBooleanType ShredFile(const char *path)
   /*
     Shred the file.
   */
-  quantum=(size_t) MagickMaxBufferExtent;
+  quantum=(size_t) MagickMinBufferExtent;
   if ((fstat(file,&file_stats) == 0) && (file_stats.st_size > 0))
-    quantum=(size_t) MagickMin(file_stats.st_size,MagickMaxBufferExtent);
+    quantum=(size_t) MagickMin(file_stats.st_size,MagickMinBufferExtent);
   length=(MagickSizeType) file_stats.st_size;
   random_info=AcquireRandomInfo();
   key=GetRandomKey(random_info,quantum);