diff --git a/setuper/setup.sh b/setuper/setup.sh
index 66dcb17..062b402 100644
--- a/setuper/setup.sh
+++ b/setuper/setup.sh
@@ -230,6 +230,16 @@ start_game_services() {
     fi
     # Create base64 auth string
     PACKMATE_AUTH=$(echo -n "$PACKMATE_WEB_LOGIN:$PACKMATE_WEB_PASSWORD" | base64)
+    PACKMATE_URL="http://${PACKMATE_LOCAL_IP}:65000"
+    # Try to obtain Packmate session cookie (JSESSIONID) using Basic auth
+    PACKMATE_COOKIE=$(curl -s -k -D - "$PACKMATE_URL/" \
+        -H "Authorization: Basic $PACKMATE_AUTH" \
+        -H "Accept: application/json" | grep -i 'Set-Cookie' | grep -i 'JSESSIONID' | head -n1 | sed 's/.*JSESSIONID=\([^;]*\).*/\1/')
+    if [ -n "$PACKMATE_COOKIE" ]; then
+        PACKMATE_COOKIE_HEADER="Cookie: JSESSIONID=$PACKMATE_COOKIE"
+    else
+        PACKMATE_COOKIE_HEADER=""
+    fi
     
     # Resolve SERVICES_DIR to absolute path
     case "$SERVICES_DIR" in
@@ -288,15 +298,28 @@ start_game_services() {
             # Add service to Packmate if Packmate is running
             if [ -n "$service_ports" ]; then
                 echo "Adding $service_name to Packmate..."
-                PACKMATE_URL="http://${PACKMATE_LOCAL_IP}:65000"
-                # Try to add each port to Packmate
+                # Try to add each exposed host port to Packmate
                 echo "$service_ports" | tr ',' '\n' | while read port; do
                     if [ -n "$port" ]; then
-                        curl -s -X POST "${PACKMATE_URL}/api/service/" \
+                        # Primary attempt (with trailing slash)
+                        status=$(curl -s -k -o /dev/null -w "%{http_code}" -X POST "${PACKMATE_URL}/api/service/" \
                             -H "Accept: application/json" \
                             -H "Authorization: Basic $PACKMATE_AUTH" \
                             -H "Content-Type: application/json" \
-                            -d "{\"name\": \"$service_name\", \"port\": $port}" || true
+                            ${PACKMATE_COOKIE_HEADER:+-H "$PACKMATE_COOKIE_HEADER"} \
+                            -d "{\"name\": \"$service_name\", \"port\": $port}" )
+                        if [ "$status" -ge 200 ] && [ "$status" -lt 300 ]; then
+                            echo "Packmate: registered $service_name port $port (status $status)"
+                        else
+                            # Fallback attempt without trailing slash
+                            status2=$(curl -s -k -o /dev/null -w "%{http_code}" -X POST "${PACKMATE_URL}/api/service" \
+                                -H "Accept: application/json" \
+                                -H "Authorization: Basic $PACKMATE_AUTH" \
+                                -H "Content-Type: application/json" \
+                                ${PACKMATE_COOKIE_HEADER:+-H "$PACKMATE_COOKIE_HEADER"} \
+                                -d "{\"name\": \"$service_name\", \"port\": $port}" )
+                            echo "Packmate: register $service_name port $port -> status $status (fallback $status2)"
+                        fi
                     fi
                 done
             fi