diff --git a/forth/boot.fs b/forth/boot.fs
index 714369a..138eda1 100644
--- a/forth/boot.fs
+++ b/forth/boot.fs
@@ -260,8 +260,7 @@ PC ORG @ 0x1e + ! ( chkPS )
     HL DECss,
     HL DECss,
     HL DECss,
-    A ORr,           ( clear carry )
-    SP SBCHLss,
+    SP SUBHLss,
     HL POPqq,
     CNC RETcc,      ( INITIAL_SP >= SP? good )
     JR, L1 BWR ( abortUnderflow )
@@ -269,8 +268,7 @@ PC ORG @ 0x1e + ! ( chkPS )
 L3 BSET ( chkRS )
     IX PUSHqq, HL POPqq,
     DE RS_ADDR LDddnn,
-    A ORr,           ( clear carry )
-    DE SBCHLss,
+    DE SUBHLss,
     CNC RETcc,      ( IX >= RS_ADDR? good )
     JR, L1 BWR ( abortUnderflow )
 
diff --git a/forth/z80c.fs b/forth/z80c.fs
index 553f5be..118f938 100644
--- a/forth/z80c.fs
+++ b/forth/z80c.fs
@@ -168,8 +168,7 @@ CODE -
     DE POPqq,
     HL POPqq,
     chkPS,
-    A ORr,
-    DE SBCHLss,
+    DE SUBHLss,
     HL PUSHqq,
 ;CODE
 
@@ -335,8 +334,7 @@ CODE CMP
     HL  POPqq,
     DE  POPqq,
     chkPS,
-    A ORr,      ( clear carry )
-    DE SBCHLss,
+    DE SUBHLss,
     ( 40 == flagsToBC )
     40 CALLnn,
     BC PUSHqq,