diff --git a/infra/seed-nodes/node/install-seed.sh b/infra/seed-nodes/node/install-seed.sh
index 6000db62a..ff9e6e899 100755
--- a/infra/seed-nodes/node/install-seed.sh
+++ b/infra/seed-nodes/node/install-seed.sh
@@ -10,11 +10,13 @@ id igneum >/dev/null 2>&1 || useradd --system --home /var/lib/igneum --shell /us
 mkdir -p /var/lib/igneum /etc/igneum /opt/igneum/bin
 chmod +x /opt/igneum/bin/*
 chown -R igneum:igneum /var/lib/igneum
+# values quoted: the launcher sources this file with `.`, so an unquoted "--testnet --netsuffix=1" ran "--netsuffix=1"
+# as a command (5 October 2026, the first testnet seed); systemd's EnvironmentFile reads the quotes too
 cat > /etc/igneum/seed.env <<EOF
-SEED_NAME=$name
-EXTERNAL_IP=$extip
-NETWORK_ARGS=$netargs
-SEED_PEERS=$peers
+SEED_NAME="$name"
+EXTERNAL_IP="$extip"
+NETWORK_ARGS="$netargs"
+SEED_PEERS="$peers"
 P2P_PORT=$p2p
 RPC_PORT=$rpc
 RPC_JSON_PORT=$rpcjson