diff --git a/shell.nix b/shell.nix
index 0e93c7272..3fa3cbdc4 100644
--- a/shell.nix
+++ b/shell.nix
@@ -47,7 +47,7 @@ let
 
     trap cleanup EXIT
 
-    export PORT_OFFSET=$(((16#$(whoami | sha256sum | head -c 16)) % 1000))
+    export PORT_OFFSET=$(((16#$(echo "fradrive $(whoami)" | sha256sum | head -c 16)) % 1000))
 
     if [[ -z "$PGHOST" ]]; then
       set -xe