diff --git a/none/tests/x86/cmpxchg8b.c b/none/tests/x86/cmpxchg8b.c
index 6e252f1..6f5b6eb 100644
--- a/none/tests/x86/cmpxchg8b.c
+++ b/none/tests/x86/cmpxchg8b.c
@@ -37,7 +37,7 @@
 
     "\tpopl %edx\n"
     "\tpopl %ecx\n"
-    "\tpopl %edx\n"
+    "\tpopl %ebx\n"
     "\tpopl %eax\n"
     "\tret\n"
     );