diff --git a/README.md b/README.md
index aa94778..ff8f3f1 100644
--- a/README.md
+++ b/README.md
@@ -36,7 +36,7 @@ Specify the GlobalProtect server URL (portal or gateway) and optional arguments.
 
 This script will pop up a [GTK WebKit2 WebView](https://webkitgtk.org/) window.
 After you succesfully complete the SAML login via web forms, the script will output
-`HOST`, `USER`, and `COOKIE` variables in a form that can be used by
+`GP_HOST`, `GP_USER`, and `GP_COOKIE` variables in a form that can be used by
 [OpenConnect](http://www.infradead.org/openconnect/juniper.html)
 (similar to the output of `openconnect --authenticate`):
 
@@ -54,12 +54,12 @@ SAML response converted to OpenConnect command line invocation:
     echo 'blahblahblah' |
         openconnect --protocol=gp --user='foo12345@corp.company.com' --usergroup=prelogin-cookie:gateway --passwd-on-stdin vpn.company.com
 
-$ echo $HOST; echo $USER; echo $COOKIE
+$ echo $GP_HOST; echo $GP_USER; echo $GP_COOKIE
 https://vpn.company.com/gateway:prelogin-cookie
 foo12345@corp.company.com
 blahblahblah'
 
-$ echo "$COOKIE" | openconnect --protocol=gp -u "$USER" --passwd-on-stdin "$HOST"
+$ echo "$GP_COOKIE" | openconnect --protocol=gp -u "$GP_USER" --passwd-on-stdin "$GP_HOST"
 ```
 
 TODO
diff --git a/gp-saml-gui.py b/gp-saml-gui.py
index 8bcf6f5..12edc4b 100755
--- a/gp-saml-gui.py
+++ b/gp-saml-gui.py
@@ -245,7 +245,7 @@ def parse_args(args = None):
             quote(un), quote(server), quote(fullpath), quote(cn), quote(cv)), file=stderr)
 
     varvals = {
-        'HOST': quote('https://%s/%s:%s' % (server, shortpath, cn)),
-        'USER': quote(un), 'COOKIE': quote(cv),
+        'GP_HOST': quote('https://%s/%s:%s' % (server, shortpath, cn)),
+        'GP_USER': quote(un), 'GP_COOKIE': quote(cv),
     }
     print('\n'.join('%s=%s' % pair for pair in varvals.items()))