diff --git a/scripts/devnet/restart_devnet.sh b/scripts/devnet/restart_devnet.sh
index 6fe25482f..1d3f6a923 100755
--- a/scripts/devnet/restart_devnet.sh
+++ b/scripts/devnet/restart_devnet.sh
@@ -1,4 +1,4 @@
-#!/usr/bin/bash
+#!/usr/bin/env bash
 set -euo pipefail
 
 ENCLAVE="devnet"
@@ -21,10 +21,23 @@ NETWORK_SUBNET=$(docker network inspect "kt-${ENCLAVE}" --format '{{range .IPAM.
 sudo ufw allow from "$NETWORK_SUBNET" to any port 4040
 sudo ufw allow from "$NETWORK_SUBNET" to any port 9060
 
-# Get proxy container IP
-PROXY_IP=$(docker inspect \
-  "$(docker ps --filter "name=helix-relay" --format '{{.ID}}' | head -1)" \
-  --format '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}')
+# Get helix-relay proxy container ID
+PROXY_CONTAINER=$(docker ps --filter "name=helix-relay" --format '{{.ID}}' | head -n 1)
+
+if [ -z "$PROXY_CONTAINER" ]; then
+    echo "ERROR: helix-relay proxy container not found or not running" >&2
+    exit 1
+fi
+
+# Get IP in the kurtosis enclave network.
+# Avoids IP concatenation when container is attached to multiple networks.
+PROXY_IP=$(docker inspect "$PROXY_CONTAINER" \
+    --format "{{(index .NetworkSettings.Networks \"kt-${ENCLAVE}\").IPAddress}}" 2>/dev/null || true)
+
+if [ -z "$PROXY_IP" ]; then
+    echo "ERROR: could not resolve IP for container $PROXY_CONTAINER" >&2
+    exit 1
+fi
 
 # Extract env vars from the service
 RELAY_KEY=$(kurtosis service inspect "$ENCLAVE" helix-relay 2>&1 | awk '/RELAY_KEY:/{print $2}')