diff --git a/ChainLoader.a b/ChainLoader.a
index 058ede2..30b0f20 100644
--- a/ChainLoader.a
+++ b/ChainLoader.a
@@ -478,7 +478,7 @@ DrvrDidSendWrite ; completion routine for the above control call..
 
             cmp.l   D0,D1
             beq.s   .sentAllOfChunk
-            and.l   #32-1,D0
+            and.l   #(32-1)*512,D0
             beq.s   .sentAllOfChunk
             bra     DrvrSendWrite