diff --git a/src/polmon.cc b/src/polmon.cc
index d279ff7..c23642c 100644
--- a/src/polmon.cc
+++ b/src/polmon.cc
@@ -228,7 +228,7 @@ asm("   .section .text.cbreak   \n"
     "   xor %ax, %ax        \n"
     "   mov %ax, %ds        \n"
     "   cli                 \n"
-    "   mov %ax, %ds        \n"
+    "   mov %ax, %ss        \n"
     "   mov $0x2000, %sp    \n"
     "   sti                 \n"
     "   pushf               \n"