diff --git a/build/misc.tcl b/build/misc.tcl
index 8d017b5f..dbec62e5 100644
--- a/build/misc.tcl
+++ b/build/misc.tcl
@@ -1211,6 +1211,10 @@ respond "*" ":midas sys1; ts imload_syseng; imload\r"
 expect ":KILL"
 respond "*" ":link sys1; ts imtran, sys1; ts imload\r"
 
+# UNTRAN
+respond "*" ":midas imlac; ts untran_untran\r"
+expect ":KILL"
+
 # IMPRNT
 respond "*" ":midas sys1; ts imprnt_syseng; imprnt\r"
 expect ":KILL"
diff --git a/doc/programs.md b/doc/programs.md
index da02d5ae..a3da490f 100644
--- a/doc/programs.md
+++ b/doc/programs.md
@@ -353,6 +353,7 @@
 - UFIND, find users.
 - ULISP, Lisp in Lisp.
 - UNTALK, split-screen comm-link program.
+- UNTRAN, untranslate an Imlac program.
 - UP/DOWN, check if host is online.
 - UPTIME, Chaosnet uptime server.
 - UPTIME, record ITS uptimes.
diff --git a/src/imlac/untran.3 b/src/imlac/untran.3
new file mode 100644
index 00000000..d4af28e7
--- /dev/null
+++ b/src/imlac/untran.3
@@ -0,0 +1,42 @@
+TITLE UNTRAN
+;THIS READS IMTRAN'D ASCII FILES (WITH BLOCK LOADER REMOVED)
+;AND WRITES A BINARY FILE FOR THE CODE REPRESENTED.
+;I.E., THIS IS AN UN-IMTRAN PROGRAM.
+;AS THERE IS NO FILE SPEC READER, YOU HAVE TO HACK
+;FILE SPECS FROM DDT.  THE INPUT FILE SPEC IS AT IFN1,IFN2
+;AND OUTPUT IS AT OFN1,OFN2.  INITIAL SETTINGS ARE 
+;ILLEGAL FOR RUNNING.  SNAME IS SET TO IMLAC;.
+A=1
+CH=2
+DSKI=10
+DSKO=11
+.MLLIT==1
+GO:	.SUSET [.SSNAM,,[SIXBIT \IMLAC\]]
+	.OPEN DSKI,ISPEC
+	 .VALUE
+	.OPEN DSKO,OSPEC
+	 .VALUE
+LP:	SETZ A,
+REPEAT 4,[
+	.IOT DSKI,CH
+	CAIGE CH,100
+	 JRST [JUMPL CH,WINDUP ? JRST .-2]
+	ANDI CH,17
+	LSH A,4
+	IOR A,CH]
+	.IOT DSKO,A
+	JRST LP
+WINDUP:	.CLOSE DSKI,
+	.CLOSE DSKO,
+	.VALUE [ASCII \:DONEî\]
+	JRST GO
+ISPEC:	0,,'DSK
+IFN1:	0
+IFN2:	0
+OSPEC:	5,,'DSK
+OFN1:	0
+OFN2:	0
+
+PATCH:
+PAT:	BLOCK 100
+END GO