diff --git a/source/debug.mac b/source/debug.mac
--- a/source/debug.mac
+++ b/source/debug.mac
@@ -47,7 +47,7 @@
 %endif
 
 	numdef INIT_MAX, 0
-	numdef EXTENSIONS, 0
+	numdef EXTENSIONS, 1
 	numdef EXT_CODE_SIZE, 64 * 1024 - 16
 	numdef EXT_CODE_DEFAULT_SIZE, 16 * 1024
 	numdef EXT_CODE_INIT_SIZE, 8 * 1024
@@ -202,12 +202,12 @@
 numdef INDOS_PROMPT,	1	; prepend '!' to prompt while InDOS
 numdef INDOS_PROMPT_NOBOOT, 1	; -... except while booted
 numdef INDOS_PROMPT_NOFLAG, 1	; -... except while only DCO flag set
-numdef EMS,		1	; support X commands
+numdef EMS,		0	; support X commands
 numdef INT,		1	; support DI command
 numdef MCB,		1	; support DM command
 numdef DX,		_PM	; support DX command (386-only)
-numdef RN,		1	; support RN command
-numdef RM,		1	; support RM command (only if _MMXSUPP=1)
+numdef RN,		0	; support RN command
+numdef RM,		0	; support RM command (only if _MMXSUPP=1)
 numdef RN_AUX,		0	; use auxiliary buffer for RN command
 numdef RM_AUX,		0	; use auxiliary buffer for RM command
 numdef MMXSUPP,		1	; support MMX specific commands