diff --git a/debbuild/22.04/DEBIAN/preinst b/debbuild/22.04/DEBIAN/preinst
index 4780ff7..926e223 100644
--- a/debbuild/22.04/DEBIAN/preinst
+++ b/debbuild/22.04/DEBIAN/preinst
@@ -1,5 +1,10 @@
 # !/bin/sh
 
+FERootDir=/usr/local/omc/htdocs/front
 # apt-get install zip
+# clear front-end old hash js files
+rm -rf ${FERootDir}/assets
+rm -rf ${FERootDir}/js
+rm -rf index.*.js
 
 
diff --git a/debbuild/DEBIAN/preinst b/debbuild/DEBIAN/preinst
index 4780ff7..0a01c14 100644
--- a/debbuild/DEBIAN/preinst
+++ b/debbuild/DEBIAN/preinst
@@ -1,5 +1,8 @@
 # !/bin/sh
 
+FERootDir=/usr/local/omc/htdocs/front
 # apt-get install zip
-
-
+# clear front-end old hash js files
+rm -rf ${FERootDir}/assets
+rm -rf ${FERootDir}/js
+rm -rf index.*.js