diff --git a/stackrc b/stackrc
index f42bd94..4fefe8d 100644
--- a/stackrc
+++ b/stackrc
@@ -712,7 +712,7 @@
 PRIVATE_NETWORK_NAME=${PRIVATE_NETWORK_NAME:-"private"}
 PUBLIC_NETWORK_NAME=${PUBLIC_NETWORK_NAME:-"public"}
 
-PUBLIC_INTERFACE=""
+PUBLIC_INTERFACE=${PUBLIC_INTERFACE:-""}
 
 # Set default screen name
 SCREEN_NAME=${SCREEN_NAME:-stack}