diff --git a/README.md b/README.md
index c25cc02..19bc5b5 100644
--- a/README.md
+++ b/README.md
@@ -64,6 +64,7 @@ docker create \
   -e PUID=1000 \
   -e PGID=1000 \
   -e TZ=Europe/London \
+  -e UMASK_SET=022 `#optional` \
   -p 8989:8989 \
   -v <path to data>:/config \
   -v <path/to/tvseries>:/tv \
@@ -88,6 +89,7 @@ services:
       - PUID=1000
       - PGID=1000
       - TZ=Europe/London
+      - UMASK_SET=022 #optional
     volumes:
       - <path to data>:/config
       - <path/to/tvseries>:/tv
@@ -107,6 +109,7 @@ Container images are configured using parameters passed at runtime (such as thos
 | `-e PUID=1000` | for UserID - see below for explanation |
 | `-e PGID=1000` | for GroupID - see below for explanation |
 | `-e TZ=Europe/London` | Specify a timezone to use EG Europe/London, this is required for Sonarr |
+| `-e UMASK_SET=022` | control permissions of files and directories created by Sonarr |
 | `-v /config` | Database and sonarr configs |
 | `-v /tv` | Location of TV library on disk |
 | `-v /downloads` | Location of download managers output directory |
@@ -193,6 +196,7 @@ Once registered you can define the dockerfile to use with `-f Dockerfile.aarch64
 
 ## Versions
 
+* **13.06.19:** - Add env variable for setting umask.
 * **10.05.19:** - Rebase to Bionic.
 * **23.03.19:** - Switching to new Base images, shift to arm32v7 tag.
 * **01.02.19:** - Multi arch images and pipeline build logic
diff --git a/readme-vars.yml b/readme-vars.yml
index f9d8396..e530c47 100644
--- a/readme-vars.yml
+++ b/readme-vars.yml
@@ -36,6 +36,9 @@ param_ports:
 param_usage_include_env: true
 param_env_vars:
   - { env_var: "TZ", env_value: "Europe/London", desc: "Specify a timezone to use EG Europe/London, this is required for Sonarr"}
+# optional env variables
+opt_param_usage_include_env: true
+opt_param_env_vars:
   - { env_var: "UMASK_SET", env_value: "022", desc: "control permissions of files and directories created by Sonarr"}
 
 # application setup block