--- a/datfiles/off/Makefile
+++ b/datfiles/off/Makefile
@@ -9,7 +9,7 @@ OCOOKIES_ROTATED=
 OCOOKIES=$(OCOOKIES_UNROTATED) $(OCOOKIES_ROTATED)
 
 STRFILE=../../util/strfile
-ROT=../../util/rot
+ROT=../../util/rot_for_build
 
 
 all:	ocookies-stamp
diff --git a/util/Makefile b/util/Makefile
index 6356e4f..0f1b35a 100644
--- a/util/Makefile
+++ b/util/Makefile
@@ -5,7 +5,7 @@
 # and make install-uman.  make clean will work properly if called in
 # this directory.
 
-all: strfile unstr rot
+all: strfile unstr rot rot_for_build
 
 strfile: strfile.o
 	$(CC) $(LDFLAGS) -o strfile strfile.o
@@ -19,5 +19,8 @@ randstr: randstr.o
 rot: rot.o
 	$(CC) -fsigned-char $(LDFLAGS) -o rot rot.o
 
+rot_for_build:
+	$(CC_FOR_BUILD) -fsigned-char $(CFLAGS_FOR_BUILD) $(LDFLAGS_FOR_BUILD) -o rot_for_build rot.c
+
 clean:
 	rm -f *.o unstr strfile randstr rot ansify
