diff --git a/libsrc/geos/inc/const.inc b/libsrc/geos/inc/const.inc
index dcbf8e479..b3aa5090a 100644
--- a/libsrc/geos/inc/const.inc
+++ b/libsrc/geos/inc/const.inc
@@ -305,6 +305,11 @@ O_GHP_DISK		=	97
 O_GHP_FNAME		=	117
 O_GHINFO_TXT		=	$a0
 
+; values for CPU_DATA - C64 memory config
+IO_IN			=	$35	;60K RAM, 4K I/O space in
+KRNL_IO_IN		=	$36	;kernal and I/O mapped into memory
+KRNL_BAS_IO_IN		=	$37	;kernal, I/O and basic mapped into memory
+
 ;values for config - C128 mmu
 CIOIN			=	$7E	;60K RAM, 4K I/O space in
 CRAM64K 		=	$7F	;64K RAM
diff --git a/libsrc/geos/inc/geossym.inc b/libsrc/geos/inc/geossym.inc
index e558a4ae0..f3d800075 100644
--- a/libsrc/geos/inc/geossym.inc
+++ b/libsrc/geos/inc/geossym.inc
@@ -106,10 +106,7 @@ msePicPtr		=	$31
 windowTop		=	$33
 windowBottom		=	$34
 leftMargin		=	$35
-IO_IN			=	$35
-KRNL_IO_IN		=	$36
 rightMargin		=	$37
-KRNL_BAS_IO_IN		=	$37
 pressFlag		=	$39
 mouseXPos		=	$3a
 mouseYPos		=	$3c