diff --git a/Makefile.in b/Makefile.in
index 8e61d6d66..3abba90c0 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -34,7 +34,7 @@ top_builddir = .
 CC = @CC@
 LEX = flex
 YACC = @YACC@
-NROFF = nroff
+NROFF = nroff -Tascii
 LIBTOOL = @LIBTOOL@
 
 # Our install program supports extra flags...