diff --git a/kernel/blockio.c b/kernel/blockio.c
index df4e306..168148b 100644
--- a/kernel/blockio.c
+++ b/kernel/blockio.c
@@ -474,5 +474,5 @@ void AllocateHMASpace (size_t lowbuffer, size_t highbuffer)
     }
     bp = b_next(bp);
   }
-  while (n--);
+  while (--n);
 }