diff --git a/Dockerfile b/Dockerfile
index f7552b8..35d00cc 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -90,7 +90,8 @@ RUN \
 # Set public environment variables.
 ENV \
     FF_OPEN_URL= \
-    FF_KIOSK=0
+    FF_KIOSK=0 \
+    FF_CUSTOM_ARGS=
 
 # Metadata.
 LABEL \
diff --git a/appdefs.yml b/appdefs.yml
index 9f2ff92..c0ad2a7 100644
--- a/appdefs.yml
+++ b/appdefs.yml
@@ -395,6 +395,16 @@ container:
         customer-facing displays.
       type: public
       default: 0
+    - name: FF_CUSTOM_ARGS
+      description: >-
+        Custom argument(s) to pass when launching {{ app.friendly_name }}.
+      type: public
+      default: 0
+      unraid_template:
+        title: "Custom Arguments"
+        display: advanced
+        required: false
+        mask: false
 
   # Volumes
   volumes: []
diff --git a/rootfs/etc/services.d/app/params b/rootfs/etc/services.d/app/params
index aaa1c23..46c42d9 100755
--- a/rootfs/etc/services.d/app/params
+++ b/rootfs/etc/services.d/app/params
@@ -20,3 +20,8 @@ fi
 if [ -n "${FF_OPEN_URL:-}" ]; then
     echo "$FF_OPEN_URL"
 fi
+
+# Custom arguments.
+if [ -n "${FF_CUSTOM_ARGS:-}" ]; then
+    eval 'for word in '$FF_CUSTOM_ARGS'; do echo "$word"; done'
+fi