diff --git a/scripts/_common.sh b/scripts/_common.sh
index 98be903..2a545e3 100644
--- a/scripts/_common.sh
+++ b/scripts/_common.sh
@@ -84,6 +84,102 @@ ynh_smart_mktemp () {
         echo "$(mktemp --directory --tmpdir="$tmpdir")"
 }
 
+#=================================================
+
+# Set ownership on files and directories with chown
+#
+# Use find to apply permissions faster on very big directories.
+#
+# usage: ynh_chown --user=user [--group=group] --file="file_or_directory" [--recursive]
+# | arg: -u, --user - Owner
+# | arg: -g, --group - Owner group (Default same as --user)
+# | arg: -f, --file - File or directory where permissions will be applied.
+# | arg: -r, --recursive - Change permissions recursively
+ynh_chown () {
+	# Declare an array to define the options of this helper.
+	local legacy_args=ugfr
+	declare -Ar args_array=( [u]=user= [g]=group= [f]=file= [r]=recursive )
+	local user
+	local group
+	local file
+	local recursive
+	# Manage arguments with getopts
+	ynh_handle_getopts_args "$@"
+	group="${group:-$user}"
+	recursive=${recursive:-0}
+
+	if [ $recursive -eq 1 ]
+	then
+		local ending_slash=""
+		if [ -d "$file" ]
+		then
+			ending_slash=/
+		fi
+
+		# With very big directories, find is way faster than chown itself.
+		# Especially because find will check the permissions and apply chown only if the permissions aren't correct.
+		# '\!' is used to have a negation on -user and -group.
+		# ' -d '\n' ' forces \n to be the delimiter of each entry instead of space. So xargs will handle correctly directories and files with spaces.
+		ynh_exec_warn_less "find \"$file$ending_slash\" \! -user $user -o \! -group $group | xargs --no-run-if-empty --delimiter='\n' chown --preserve-root $user:$group"
+	else
+		ynh_exec_warn_less chown $user:$group \"$file\"
+	fi
+}
+
+# Set permissions on files and directories with chmod
+#
+# Use find to apply permissions faster on very big directories.
+#
+# usage: ynh_chmod --permissions=0755 --file="file_or_directory" [--recursive]  [--type=file/dir]
+# | arg: -p, --permissions - Permissions to apply with chmod.
+# | arg: -f, --file - File or directory where permissions will be applied.
+# | arg: -r, --recursive - Change permissions recursively
+# | arg: -t, --type - Apply permissions only on regular files (file) or directories (dir)
+ynh_chmod () {
+	# Declare an array to define the options of this helper.
+	local legacy_args=pfrt
+	declare -Ar args_array=( [p]=permissions= [f]=file= [r]=recursive [t]=type= )
+	local permissions
+	local file
+	local recursive
+	local type
+	# Manage arguments with getopts
+	ynh_handle_getopts_args "$@"
+	recursive=${recursive:-0}
+	type="${type:-}"
+
+	if [ -n "$type" ] && [ "$type" != "file" ] && [ "$type" != "dir" ]
+	then
+		ynh_print_err --message="The value \"$type\" for --type is not recognized."
+		type=""
+	else
+		if [ "$type" == "file" ]
+		then
+			type="-type f"
+		elif [ "$type" == "dir" ]
+		then
+			type="-type d"
+		fi
+	fi
+
+	if [ $recursive -eq 1 ]
+	then
+		local ending_slash=""
+		if [ -d "$file" ]
+		then
+			ending_slash=/
+		fi
+
+		# With very big directories, find is way faster than chmod itself.
+		# Especially because find will check the permissions and apply chmod only if the permissions aren't correct.
+		# '\!' is used to have a negation on -perm.
+		# ' -d '\n' ' forces \n to be the delimiter of each entry instead of space. So xargs will handle correctly directories and files with spaces.
+		ynh_exec_warn_less "find \"$file$ending_slash\" $type \! -perm $permissions | xargs --no-run-if-empty --delimiter='\n' chmod --preserve-root $permissions"
+	else
+		ynh_exec_warn_less chmod $permissions \"$file\"
+	fi
+}
+
 #=================================================
 # FUTURE OFFICIAL HELPERS
 #=================================================
diff --git a/scripts/install b/scripts/install
index 51d8b0f..ba34521 100755
--- a/scripts/install
+++ b/scripts/install
@@ -305,10 +305,10 @@ ynh_multimedia_addaccess $app
 
 # Fix app ownerships & permissions
 chown -R $app: "$final_path" "$datadir"
-find $final_path/ -type f -print0 | xargs -0 chmod 0644
-find $final_path/ -type d -print0 | xargs -0 chmod 0755
-find $datadir/ -type f -print0 | xargs -0 chmod 0640
-find $datadir/ -type d -print0 | xargs -0 chmod 0750
+ynh_chmod --permissions=0644 --file="$final_path" --recursive --type=file
+ynh_chmod --permissions=0755 --file="$final_path" --recursive --type=dir
+ynh_chmod --permissions=0640 --file="$datadir" --recursive --type=file
+ynh_chmod --permissions=0750 --file="$datadir" --recursive --type=dir
 chmod 640 "$final_path/config/config.php"
 chmod 755 /home/yunohost.app
 
diff --git a/scripts/restore b/scripts/restore
index 44f8384..7276aef 100755
--- a/scripts/restore
+++ b/scripts/restore
@@ -133,7 +133,8 @@ mkdir -p "$datadir"
 #=================================================
 
 # Fix app ownerships & permissions
-chown -R $app: "$final_path" "$datadir"
+ynh_chown --user=$app --file="$final_path" --recursive
+ynh_chown --user=$app --file="$datadir" --recursive
 chmod 640 "$final_path/config/config.php"
 chmod 755 /home/yunohost.app
 
diff --git a/scripts/upgrade b/scripts/upgrade
index 205cc51..8a85b90 100755
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -222,7 +222,9 @@ then
     last_major_version=${last_version%%.*}
 
     # Set write access for the following commands
-    chown -R $app: "$final_path" "$datadir"
+    chown -R $app: "$final_path"
+    # Change of owner and group if files in datadir does not have the right permissions
+    ynh_chown --user=$app --file="$datadir" --recursive
 
     # Print the current version number of Nextcloud
     exec_occ -V
@@ -307,7 +309,8 @@ EOF
         ynh_secure_remove --file="$tmpdir"
 
         # Set write access for the following commands
-        chown -R $app: "$final_path" "$datadir"
+        chown -R $app: "$final_path"
+        ynh_chown --user=$app --file="$datadir" --recursive
 
         # Upgrade Nextcloud (SUCCESS = 0, UP_TO_DATE = 3)
         exec_occ maintenance:mode --off
@@ -417,11 +420,15 @@ exec_occ background:cron
 #=================================================
 
 # Fix app ownerships & permissions
-chown -R $app: "$final_path" "$datadir"
-find $final_path/ -type f -print0 | xargs -0 chmod 0644
-find $final_path/ -type d -print0 | xargs -0 chmod 0755
-find $datadir/ -type f -print0 | xargs -0 chmod 0640
-find $datadir/ -type d -print0 | xargs -0 chmod 0750
+chown -R $app: "$final_path"
+# Change of owner and group if files in datadir does not have the right permissions
+ynh_chown --user=$app --file="$datadir" --recursive
+ynh_chmod --permissions=0644 --file="$final_path" --recursive --type=file
+ynh_chmod --permissions=0755 --file="$final_path" --recursive --type=dir
+# Change permissions if the file in datadir does not have the right permissions
+ynh_chmod --permissions=0640 --file="$datadir" --recursive --type=file
+# Change permissions if directories in datadir does not have the right permissions
+ynh_chmod --permissions=0750 --file="$datadir" --recursive --type=dir
 chmod 640 "$final_path/config/config.php"
 chmod 755 /home/yunohost.app