diff --git a/docs/brave/README.md b/docs/brave/README.md
index a47d9f7..a9d0629 100644
--- a/docs/brave/README.md
+++ b/docs/brave/README.md
@@ -10,3 +10,5 @@ This Image contains a browser-accessible version of [Brave](https://brave.com/).
 
 * `LAUNCH_URL` - The default URL the browser launches to when created.
 * `APP_ARGS` - Additional arguments to pass to the browser when launched.
+* `KASM_RESTRICTED_FILE_CHOOSER` - Confine "File Upload" and "File Save"
+  dialogs to ~/Desktop. On by default.
diff --git a/docs/chrome/README.md b/docs/chrome/README.md
index 3f4d9d2..9ae81d3 100644
--- a/docs/chrome/README.md
+++ b/docs/chrome/README.md
@@ -10,3 +10,5 @@ This Image contains a browser-accessible version of [Google Chrome](https://www.
 
 * `LAUNCH_URL` - The default URL the browser launches to when created.
 * `APP_ARGS` - Additional arguments to pass to the browser when launched.
+* `KASM_RESTRICTED_FILE_CHOOSER` - Confine "File Upload" and "File Save"
+  dialogs to ~/Desktop. On by default.
diff --git a/docs/edge/README.md b/docs/edge/README.md
index 171a853..61f4d8e 100644
--- a/docs/edge/README.md
+++ b/docs/edge/README.md
@@ -10,3 +10,5 @@ This Image contains a browser-accessible version of [Microsoft Edge Insider Prev
 
 * `LAUNCH_URL` - The default URL the browser launches to when created.
 * `APP_ARGS` - Additional arguments to pass to the browser when launched.
+* `KASM_RESTRICTED_FILE_CHOOSER` - Confine "File Upload" and "File Save"
+  dialogs to ~/Desktop. On by default.
diff --git a/docs/firefox/README.md b/docs/firefox/README.md
index 99b15d7..af5eb8a 100644
--- a/docs/firefox/README.md
+++ b/docs/firefox/README.md
@@ -10,3 +10,5 @@ This Image contains a browser-accessible version of [Mozilla Firefox](https://ww
 
 * `LAUNCH_URL` - The default URL the browser launches to when created.
 * `APP_ARGS` - Additional arguments to pass to the browser when launched.
+* `KASM_RESTRICTED_FILE_CHOOSER` - Confine "File Upload" and "File Save"
+  dialogs to ~/Desktop. On by default.
diff --git a/docs/tor-browser/README.md b/docs/tor-browser/README.md
index 560f5d3..a0873ed 100644
--- a/docs/tor-browser/README.md
+++ b/docs/tor-browser/README.md
@@ -8,4 +8,6 @@ This Image contains a browser-accessible version of [Tor Browser](https://www.to
 
 # Environment Variables
 
-* `APP_ARGS` - Additional arguments to pass to the application when launched.
\ No newline at end of file
+* `APP_ARGS` - Additional arguments to pass to the application when launched.
+* `KASM_RESTRICTED_FILE_CHOOSER` - Confine "File Upload" and "File Save"
+  dialogs to ~/Desktop. On by default.