diff --git a/ChangeLog b/ChangeLog
index 85388f2f5..29c5c27fa 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2013-09-23  Tim Hardeck  <thardeck>
+
+	* util/grub.d/10_hurd.in: Filter out character for the class.
+	* util/grub.d/10_kfreebsd.in: Likewise.
+	* util/grub.d/10_linux.in: Likewise.
+	* util/grub.d/20_linux_xen.in: Likewise.
+
 2013-09-23  Melki Christian  <Christian.melki@saabgroup.com>
 
 	* grub-core/bus/usb/usbhub.c (poll_nonroot_hub): Fix the type of
diff --git a/util/grub.d/10_hurd.in b/util/grub.d/10_hurd.in
index 00efd68cb..293b5da03 100644
--- a/util/grub.d/10_hurd.in
+++ b/util/grub.d/10_hurd.in
@@ -32,7 +32,7 @@ if [ "x${GRUB_DISTRIBUTOR}" = "x" ] ; then
   OS=GNU
 else
   OS="${GRUB_DISTRIBUTOR} GNU/Hurd"
-  CLASS="--class $(echo ${GRUB_DISTRIBUTOR} | tr 'A-Z' 'a-z' | cut -d' ' -f1) ${CLASS}"
+  CLASS="--class $(echo ${GRUB_DISTRIBUTOR} | tr 'A-Z' 'a-z' | cut -d' ' -f1|LC_ALL=C sed 's,[^[:alnum:]_],_,g') ${CLASS}"
 fi
 
 at_least_one=false
diff --git a/util/grub.d/10_kfreebsd.in b/util/grub.d/10_kfreebsd.in
index c123ceb2e..9646998a2 100644
--- a/util/grub.d/10_kfreebsd.in
+++ b/util/grub.d/10_kfreebsd.in
@@ -30,7 +30,7 @@ CLASS="--class os"
 case "${GRUB_DISTRIBUTOR}" in
   Debian)
 	OS="${GRUB_DISTRIBUTOR} GNU/kFreeBSD"
-	CLASS="--class $(echo ${GRUB_DISTRIBUTOR} | tr 'A-Z' 'a-z' | cut -d' ' -f1) --class gnu-kfreebsd --class gnu ${CLASS}"
+	CLASS="--class $(echo ${GRUB_DISTRIBUTOR} | tr 'A-Z' 'a-z' | cut -d' ' -f1|LC_ALL=C sed 's,[^[:alnum:]_],_,g') --class gnu-kfreebsd --class gnu ${CLASS}"
   ;;
   *)
 	OS="FreeBSD"
diff --git a/util/grub.d/10_linux.in b/util/grub.d/10_linux.in
index 0724e16e7..26f3e0701 100644
--- a/util/grub.d/10_linux.in
+++ b/util/grub.d/10_linux.in
@@ -32,7 +32,7 @@ if [ "x${GRUB_DISTRIBUTOR}" = "x" ] ; then
   OS=GNU/Linux
 else
   OS="${GRUB_DISTRIBUTOR} GNU/Linux"
-  CLASS="--class $(echo ${GRUB_DISTRIBUTOR} | tr 'A-Z' 'a-z' | cut -d' ' -f1) ${CLASS}"
+  CLASS="--class $(echo ${GRUB_DISTRIBUTOR} | tr 'A-Z' 'a-z' | cut -d' ' -f1|LC_ALL=C sed 's,[^[:alnum:]_],_,g') ${CLASS}"
 fi
 
 # loop-AES arranges things so that /dev/loop/X can be our root device, but
diff --git a/util/grub.d/20_linux_xen.in b/util/grub.d/20_linux_xen.in
index 6651cbcf0..f488e2c2c 100644
--- a/util/grub.d/20_linux_xen.in
+++ b/util/grub.d/20_linux_xen.in
@@ -32,7 +32,7 @@ if [ "x${GRUB_DISTRIBUTOR}" = "x" ] ; then
   OS=GNU/Linux
 else
   OS="${GRUB_DISTRIBUTOR} GNU/Linux"
-  CLASS="--class $(echo ${GRUB_DISTRIBUTOR} | tr 'A-Z' 'a-z' | cut -d' ' -f1) ${CLASS}"
+  CLASS="--class $(echo ${GRUB_DISTRIBUTOR} | tr 'A-Z' 'a-z' | cut -d' ' -f1|LC_ALL=C sed 's,[^[:alnum:]_],_,g') ${CLASS}"
 fi
 
 # loop-AES arranges things so that /dev/loop/X can be our root device, but