diff --git a/service/slidge/slidge.env.template b/service/slidge/slidge.env.template
index 454f589..b1c50a3 100644
--- a/service/slidge/slidge.env.template
+++ b/service/slidge/slidge.env.template
@@ -4,7 +4,7 @@ SLIDGE_SECRET=${PROSODY_SLIDGE_PASSWORD}
 SLIDGE_SECRET_KEY=${SLIDGE_SECRET_KEY}
 SLIDGE_HOME_DIR=/var/lib/slidge
 SLIDGE_USER_JID_VALIDATOR=.*@${PROSODY_HOST}
-SLIDGE_UPLOAD_SERVICE=${PROSODY_HOST_EXTERNAL}
+SLIDGE_UPLOAD_SERVICE=upload.${PROSODY_HOST}
 
 # Options for Prosody component configuration.
 PROSODY_COMPONENT_PASSWORD=${PROSODY_SLIDGE_PASSWORD}