diff --git a/tests/simulation/run_node.sh b/tests/simulation/run_node.sh
index f2bf1f10c..8de368289 100755
--- a/tests/simulation/run_node.sh
+++ b/tests/simulation/run_node.sh
@@ -15,20 +15,17 @@ if [ "${NAT:-}" == "1" ]; then
   NAT_FLAG="--nat:extip:$(curl -s ifconfig.me)"
 fi
 
+FIRST_VALIDATOR_IDX=$(printf '%07d' $(( (NUM_VALIDATORS / ($NUM_NODES + 1)) * $1 )))
+LAST_VALIDATOR_IDX=$(printf '%07d' $(( (NUM_VALIDATORS / ($NUM_NODES + 1)) * ($1 + 1) - 1 )))
+
+mkdir -p $DATA_DIR/validators
+rm -f $DATA_DIR/validators/*
+eval cp ${VALIDATORS_DIR}/v{$FIRST_VALIDATOR_IDX..$LAST_VALIDATOR_IDX}.privkey $DATA_DIR/validators
+
 $BEACON_NODE_BIN \
   --network:$NETWORK_METADATA_FILE \
   --dataDir:$DATA_DIR \
   --nodename:${1} \
-  --validator:${V_PREFIX}0.privkey \
-  --validator:${V_PREFIX}1.privkey \
-  --validator:${V_PREFIX}2.privkey \
-  --validator:${V_PREFIX}3.privkey \
-  --validator:${V_PREFIX}4.privkey \
-  --validator:${V_PREFIX}5.privkey \
-  --validator:${V_PREFIX}6.privkey \
-  --validator:${V_PREFIX}7.privkey \
-  --validator:${V_PREFIX}8.privkey \
-  --validator:${V_PREFIX}9.privkey \
   --tcpPort:$PORT \
   --udpPort:$PORT \
   $NAT_FLAG \
diff --git a/tests/simulation/start.sh b/tests/simulation/start.sh
index 9be7bae38..9795bd089 100755
--- a/tests/simulation/start.sh
+++ b/tests/simulation/start.sh
@@ -7,8 +7,8 @@ set -eu
 
 # Set a default value for the env vars usually supplied by nimbus Makefile
 
-NUM_VALIDATORS=${VALIDATORS:-100}
-NUM_NODES=${NODES:-9}
+export NUM_VALIDATORS=${VALIDATORS:-100}
+export NUM_NODES=${NODES:-9}
 
 cd "$SIM_ROOT"
 mkdir -p "$SIMULATION_DIR"