diff --git a/.tool-versions b/.tool-versions
new file mode 100644
index 0000000..668a388
--- /dev/null
+++ b/.tool-versions
@@ -0,0 +1 @@
+golang 1.24.1
diff --git a/multinode/send_only_node.go b/multinode/send_only_node.go
index a646897..cd76f49 100644
--- a/multinode/send_only_node.go
+++ b/multinode/send_only_node.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"net/url"
+	"strconv"
 	"sync"
 
 	"github.com/smartcontractkit/chainlink-common/pkg/logger"
@@ -111,7 +112,7 @@ func (s *sendOnlyNode[CHAIN_ID, RPC]) start() {
 	}
 	s.setState(nodeStateDialed)
 
-	if s.chainID.String() == "0" {
+	if s.chainID.String() == strconv.Itoa(NullClientChainID) {
 		// Skip verification if chainID is zero
 		s.log.Warn("sendonly rpc ChainID verification skipped")
 	} else {
diff --git a/multinode/send_only_node_test.go b/multinode/send_only_node_test.go
index 45b0b06..bfd8149 100644
--- a/multinode/send_only_node_test.go
+++ b/multinode/send_only_node_test.go
@@ -55,13 +55,13 @@ func TestStartSendOnlyNode(t *testing.T) {
 		tests.AssertEventually(t, func() bool { return s.State() == nodeStateUnusable })
 		tests.RequireLogMessage(t, observedLogs, "Dial failed: SendOnly Node is unusable")
 	})
-	t.Run("Default ChainID(0) produces warn and skips checks", func(t *testing.T) {
+	t.Run("Default ChainID(1399100) produces warn and skips checks", func(t *testing.T) {
 		t.Parallel()
 		lggr, observedLogs := logger.TestObserved(t, zap.WarnLevel)
 		client := newMockSendOnlyClient[ID](t)
 		client.On("Close").Once()
 		client.On("Dial", mock.Anything).Return(nil).Once()
-		s := NewSendOnlyNode(lggr, makeMockNodeMetrics(t), url.URL{}, t.Name(), NewIDFromInt(0), client)
+		s := NewSendOnlyNode(lggr, makeMockNodeMetrics(t), url.URL{}, t.Name(), NewIDFromInt(1399100), client)
 
 		defer func() { assert.NoError(t, s.Close()) }()
 		err := s.Start(tests.Context(t))
diff --git a/multinode/utils.go b/multinode/utils.go
index ace59ba..ca5f51c 100644
--- a/multinode/utils.go
+++ b/multinode/utils.go
@@ -9,6 +9,8 @@ import (
 	"github.com/jpillora/backoff"
 )
 
+const NullClientChainID = 1399100
+
 func RandomID() ID {
 	// #nosec G404
 	id := rand.Int63n(math.MaxInt32) + 10000