diff --git a/jdatadst.c b/jdatadst.c
index 436e663..7a40e4f 100644
--- a/jdatadst.c
+++ b/jdatadst.c
@@ -72,7 +72,7 @@
   /* Allocate the output buffer --- it will be released when done with image */
   dest->buffer = (JOCTET *)
       (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
-                                  OUTPUT_BUF_SIZE * SIZEOF(JOCTET));
+                                  OUTPUT_BUF_SIZE * sizeof(JOCTET));
 
   dest->pub.next_output_byte = dest->buffer;
   dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
@@ -216,7 +216,7 @@
   if (cinfo->dest == NULL) {    /* first time for this JPEG object? */
     cinfo->dest = (struct jpeg_destination_mgr *)
       (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
-                                  SIZEOF(my_destination_mgr));
+                                  sizeof(my_destination_mgr));
   }
 
   dest = (my_dest_ptr) cinfo->dest;
@@ -254,7 +254,7 @@
   if (cinfo->dest == NULL) {    /* first time for this JPEG object? */
     cinfo->dest = (struct jpeg_destination_mgr *)
       (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
-                                  SIZEOF(my_mem_destination_mgr));
+                                  sizeof(my_mem_destination_mgr));
   }
 
   dest = (my_mem_dest_ptr) cinfo->dest;