diff --git a/crc16.c b/crc16.c
index 2e1e6e3..02453ae 100644
--- a/crc16.c
+++ b/crc16.c
@@ -24,10 +24,11 @@ asm (
         "main:             \n"
         "  push %bp        \n"
         "  mov %sp, %bp    \n"
-        "  mov 6(%bp), %si \n"
+        "  mov 8(%bp), %si \n"
         "  push (%si)      \n"
         "  call crc16      \n"
-        "  mov 8(%bp), %di \n"
+        "  add $0x2, %sp   \n"
+        "  mov 6(%bp), %di \n"
         "  mov %ax, (%di)  \n"
         "  pop %bp         \n"
         "  lret $4         \n"