diff --git a/build/pdp10-kl/boot b/build/pdp10-kl/boot
index f5cb6ab3..18c85995 100644
--- a/build/pdp10-kl/boot
+++ b/build/pdp10-kl/boot
@@ -7,7 +7,7 @@ set lpt dis
 set dc disable
 set pd ena
 set pd on
-set mta type=b
+set mta enabled type=b
 at mta0 out/pdp10-kl/minsrc.tape
 set rpa0 rp04
 set rpa1 rp04
diff --git a/build/pdp10-kl/boot2 b/build/pdp10-kl/boot2
index 91227711..d6d3521f 100644
--- a/build/pdp10-kl/boot2
+++ b/build/pdp10-kl/boot2
@@ -7,7 +7,7 @@ set lpt dis
 set dc disable
 set pd ena
 set pd on
-set mta type=b
+set mta enabled type=b
 at mta0 out/pdp10-kl/sources.tape
 set rpa0 rp04
 set rpa1 rp04
diff --git a/build/pdp10-kl/init b/build/pdp10-kl/init
index fddac251..ce49ceda 100644
--- a/build/pdp10-kl/init
+++ b/build/pdp10-kl/init
@@ -5,7 +5,7 @@ set rpb dis
 set tua dis
 set lpt dis
 set dc disable
-set mta type=a
+set mta enabled type=a
 at mta0 out/pdp10-kl/kl-magdmp.tap
 at mta5 out/pdp10-kl/kl-minsys.tape
 set rpa0 rp04
diff --git a/build/pdp10-kl/run b/build/pdp10-kl/run
index d5aadd67..75cc3d3d 100644
--- a/build/pdp10-kl/run
+++ b/build/pdp10-kl/run
@@ -17,7 +17,7 @@ at tty line=13,10017 speed=9600
 at tty line=12,10015 speed=9600
 set pd ena
 set pd on
-set mta type=b
+set mta enabled type=b
 set rpa0 rp04
 set rpa1 rp04
 set rpa2 rp04