diff --git a/src/osdef.sh b/src/osdef.sh
index 59ef55d..ead1aef 100755
--- a/src/osdef.sh
+++ b/src/osdef.sh
@@ -18,6 +18,11 @@
   srcdir=.
 fi
 
+# Make sure collation works as expected
+# swedish range [a-z] does not match 'w'
+export LC_COLLATE=C
+export LC_ALL=
+
 rm -f core* *.core
 
 cat << EOF > osdef0.c