diff --git a/include/asm-x86/asm.h b/include/asm-x86/asm.h
index 57750a9..9722032 100644
--- a/include/asm-x86/asm.h
+++ b/include/asm-x86/asm.h
@@ -28,6 +28,8 @@
 #define _ASM_SUB	__ASM_SIZE(sub)
 #define _ASM_XADD	__ASM_SIZE(xadd)
 #define _ASM_AX		__ASM_REG(ax)
+#define _ASM_BX		__ASM_REG(bx)
+#define _ASM_CX		__ASM_REG(cx)
 #define _ASM_DX		__ASM_REG(dx)
 
 /* Exception table entry */