diff --git a/src/dorkbox/network/Client.kt b/src/dorkbox/network/Client.kt
index 9c53e6ba..1fe24b8c 100644
--- a/src/dorkbox/network/Client.kt
+++ b/src/dorkbox/network/Client.kt
@@ -228,6 +228,9 @@ open class Client<CONNECTION : Connection>(config: Configuration = Configuration
                                 ipcPublicationId: Int = AeronConfig.IPC_HANDSHAKE_STREAM_ID_SUB,
                                 ipcSubscriptionId: Int = AeronConfig.IPC_HANDSHAKE_STREAM_ID_PUB,
                                 connectionTimeoutMS: Long = 30_000L, reliable: Boolean = true) {
+
+        require(connectionTimeoutMS >= 0) { "connectionTimeoutMS '$connectionTimeoutMS' is invalid. It must be >0" }
+
         // this will exist ONLY if we are reconnecting via a "disconnect" callback
         lockStepForReconnect.value?.doWait()
 
diff --git a/src/dorkbox/network/handshake/ClientHandshake.kt b/src/dorkbox/network/handshake/ClientHandshake.kt
index 243c89be..2555b559 100644
--- a/src/dorkbox/network/handshake/ClientHandshake.kt
+++ b/src/dorkbox/network/handshake/ClientHandshake.kt
@@ -138,7 +138,7 @@ internal class ClientHandshake<CONNECTION: Connection>(private val crypto: Crypt
         val pollIdleStrategy = endPoint.config.pollIdleStrategy
 
         val startTime = System.currentTimeMillis()
-        while (System.currentTimeMillis() - startTime < connectionTimeoutMS) {
+        while (connectionTimeoutMS == 0L || System.currentTimeMillis() - startTime < connectionTimeoutMS) {
             // NOTE: regarding fragment limit size. Repeated calls to '.poll' will reassemble a fragment.
             //   `.poll(handler, 4)` == `.poll(handler, 2)` + `.poll(handler, 2)`
             pollCount = subscription.poll(handler, 1)
@@ -183,7 +183,7 @@ internal class ClientHandshake<CONNECTION: Connection>(private val crypto: Crypt
         val pollIdleStrategy = endPoint.config.pollIdleStrategy
 
         var startTime = System.currentTimeMillis()
-        while (System.currentTimeMillis() - startTime < connectionTimeoutMS) {
+        while (connectionTimeoutMS == 0L || System.currentTimeMillis() - startTime < connectionTimeoutMS) {
             // NOTE: regarding fragment limit size. Repeated calls to '.poll' will reassemble a fragment.
             //   `.poll(handler, 4)` == `.poll(handler, 2)` + `.poll(handler, 2)`
             pollCount = subscription.poll(handler, 1)