diff --git a/src/emu/operations.rs b/src/emu/operations.rs
index 055a41a..c3265c5 100644
--- a/src/emu/operations.rs
+++ b/src/emu/operations.rs
@@ -112,7 +112,7 @@ pub fn cmpsb(flags: &mut Flags,
              si: &mut Reg,
              es: &mut Reg,
              di: &mut Reg) {
-  string_op!((u8, flags, rep, cx, di=di, zf=flags.zf), {
+  string_op!((u8, flags, rep, cx, si=si, di=di, zf=flags.zf), {
     let src = <FarPtr as RValue<u8>>::read(&FarPtr { bus: bus, segment: seg, offset: si.read() });
     let dst = <FarPtr as RValue<u8>>::read(&FarPtr { bus: bus, segment: es.read(), offset: di.read() });
 
@@ -128,7 +128,7 @@ pub fn cmpsw(flags: &mut Flags,
              si: &mut Reg,
              es: &mut Reg,
              di: &mut Reg) {
-  string_op!((u16, flags, rep, cx, di=di, zf=flags.zf), {
+  string_op!((u16, flags, rep, cx, si=si, di=di, zf=flags.zf), {
     let src = <FarPtr as RValue<u16>>::read(&FarPtr { bus: bus, segment: seg, offset: si.read() });
     let dst = <FarPtr as RValue<u16>>::read(&FarPtr { bus: bus, segment: es.read(), offset: di.read() });