diff --git a/base b/base
index 0dc71fd1b..8efd64995 160000
--- a/base
+++ b/base
@@ -1 +1 @@
-Subproject commit 0dc71fd1b43cf41d116404ad59ab2c5c9fa50898
+Subproject commit 8efd649950d296fc79d8ce5ef50060ef815f6f5a
diff --git a/platform/kobo/koreader.sh b/platform/kobo/koreader.sh
index c2220206a..05381aaa7 100755
--- a/platform/kobo/koreader.sh
+++ b/platform/kobo/koreader.sh
@@ -362,9 +362,22 @@ while [ ${RETURN_VALUE} -ne 0 ]; do
 
     if [ ${RETURN_VALUE} -eq ${KO_RC_USBMS} ]; then
         # User requested an USBMS session, setup the tool outside of onboard
-        mkdir -p "/tmp/usbms"
-        if ! ./tar xzf "./data/KoboUSBMS.tar.gz" -C "/tmp/usbms"; then
-            echo "Couldn't unpack KoboUSBMS to /tmp/usbms, restarting KOReader . . ." >>crash.log 2>&1
+        USBMS_HOME="/mnt/usbms"
+        mkdir -p "${USBMS_HOME}"
+        # We're using a custom tmpfs in case /tmp is too small (mainly because we may need to import a large CJK font in there...)
+        if ! mount -t tmpfs tmpfs ${USBMS_HOME} -o defaults,size=32M,mode=1777,noatime; then
+            echo "Failed to create the USBMS tmpfs, restarting KOReader . . ." >>crash.log 2>&1
+            continue
+        fi
+
+        if ! ./tar xzf "./data/KoboUSBMS.tar.gz" -C "${USBMS_HOME}"; then
+            echo "Couldn't unpack KoboUSBMS, restarting KOReader . . ." >>crash.log 2>&1
+            if ! umount "${USBMS_HOME}"; then
+                echo "Couldn't unmount the USBMS tmpfs, shutting down in 30 sec!" >>crash.log 2>&1
+                sleep 30
+                poweroff -f
+            fi
+            rm -rf "${USBMS_HOME}"
             continue
         fi
 
@@ -375,9 +388,22 @@ while [ ${RETURN_VALUE} -ne 0 ]; do
             usbms_lang="C"
         fi
 
+        # If the language is CJK, copy the CJK font, too...
+        case "${usbms_lang}" in
+            ja* | ko* | zh*)
+                cp -pf "${KOREADER_DIR}/fonts/noto/NotoSansCJKsc-Regular.otf" "${USBMS_HOME}/resources/fonts/NotoSansCJKsc-Regular.otf"
+                ;;
+        esac
+
         # Here we go!
-        if ! cd "/tmp/usbms"; then
-            echo "Couldn't chdir to /tmp/usbms, restarting KOReader . . ." >>crash.log 2>&1
+        if ! cd "${USBMS_HOME}"; then
+            echo "Couldn't chdir to ${USBMS_HOME}, restarting KOReader . . ." >>crash.log 2>&1
+            if ! umount "${USBMS_HOME}"; then
+                echo "Couldn't unmount the USBMS tmpfs, shutting down in 30 sec!" >>crash.log 2>&1
+                sleep 30
+                poweroff -f
+            fi
+            rm -rf "${USBMS_HOME}"
             continue
         fi
         env LANGUAGE="${usbms_lang}" ./usbms
@@ -401,7 +427,14 @@ while [ ${RETURN_VALUE} -ne 0 ]; do
             sleep 30
             poweroff -f
         fi
-        rm -rf "/tmp/usbms"
+
+        # Tear down the tmpfs...
+        if ! umount "${USBMS_HOME}"; then
+            logger -p "DAEMON.CRIT" -t "koreader.sh[$$]" "Couldn't unmount the USBMS tmpfs, shutting down in 30 sec!"
+            sleep 30
+            poweroff -f
+        fi
+        rm -rf "${USBMS_HOME}"
     fi
 done