diff --git a/build/build.tcl b/build/build.tcl
index c95deefe..b6e5b97b 100644
--- a/build/build.tcl
+++ b/build/build.tcl
@@ -453,10 +453,8 @@ type "purify\033g"
 respond ":PDUMP DSK:.MAIL.;COMSAT LAUNCH" "\r"
 
 respond "*" ":kill\r"
-respond "*" ":job comsat\r"
-respond "*" ":load .mail.;comsat launch\r"
-respond "*" "debug/-1\r"
-type "mfinit\033g"
+
+initialize_comsat
 
 respond "*" ":link emacs;rmail \021:ej,emacs;\[rmai\] >\r"
 
diff --git a/build/klh10/build.tcl b/build/klh10/build.tcl
index 8248b589..91c39de9 100644
--- a/build/klh10/build.tcl
+++ b/build/klh10/build.tcl
@@ -43,4 +43,11 @@ proc quit_emulator {} {
     respond "Confirm" "y\r"
 }
 
+proc initialize_comsat {} {
+    respond "*" ":job comsat\r"
+    respond "*" ":load .mail.;comsat launch\r"
+    respond "*" "debug/-1\r"
+    type "mfinit\033g"
+}
+
 source ../build.tcl
diff --git a/build/simh/build.tcl b/build/simh/build.tcl
index a2384488..a2aa7168 100644
--- a/build/simh/build.tcl
+++ b/build/simh/build.tcl
@@ -36,4 +36,13 @@ proc quit_emulator {} {
     respond "sim>" "q\r"
 }
 
+proc initialize_comsat {} {
+    # commented out because you cannot run COMSAT initialization without network
+    # support
+    #respond "*" ":job comsat\r"
+    #respond "*" ":load .mail.;comsat launch\r"
+    #respond "*" "debug/-1\r"
+    #type "mfinit\033g"
+}
+
 source build/build.tcl