diff --git a/contrib/groff/src/preproc/eqn/neqn.sh b/contrib/groff/src/preproc/eqn/neqn.sh
index 745599b46a7b..dadf8f16a6bb 100644
--- a/contrib/groff/src/preproc/eqn/neqn.sh
+++ b/contrib/groff/src/preproc/eqn/neqn.sh
@@ -7,7 +7,7 @@
 case "${LC_ALL-${LC_CTYPE-${LANG}}}" in
   *.UTF-8)
     T=utf8 ;;
-  iso_8859_1 | *.ISO-8859-1 | *.ISO_8859-1)
+  iso_8859_1 | *.ISO*8859-1 | *.ISO*8859-15)
     T=latin1 ;;
   *.IBM-1047)
     T=cp1047 ;;
diff --git a/contrib/groff/src/roff/nroff/nroff.sh b/contrib/groff/src/roff/nroff/nroff.sh
index e16472e61617..82f9031cd8c5 100755
--- a/contrib/groff/src/roff/nroff/nroff.sh
+++ b/contrib/groff/src/roff/nroff/nroff.sh
@@ -17,7 +17,7 @@ case "`#locale charmap 2>/dev/null`" in
     case "${LC_ALL-${LC_CTYPE-${LANG}}}" in
       *.UTF-8)
         T=-Tutf8 ;;
-      iso_8859_1 | *.ISO-8859-1 | *.ISO_8859-1)
+      iso_8859_1 | *.ISO*8859-1 | *.ISO*8859-15)
         T=-Tlatin1 ;;
       *.IBM-1047)
         T=-Tcp1047 ;;