diff --git a/src/mits_s/config.849 b/src/mits_s/config.850
similarity index 99%
rename from src/mits_s/config.849
rename to src/mits_s/config.850
index 73b88287..04454cdb 100755
--- a/src/mits_s/config.849
+++ b/src/mits_s/config.850
@@ -17,7 +17,7 @@
 
 .if z %opsys-"IT		;if under ITS
 	.macro $insrt fn1,fn2
-		.insrt MC:MITS.S;fn1 fn2
+		.insrt MITS.S;fn1 fn2
 	.endm
 .endc
 .if z %opsys-"TW		;if under 20X