diff --git a/Realtime/src/commonMain/kotlin/io/github/jan/supabase/realtime/RealtimeImpl.kt b/Realtime/src/commonMain/kotlin/io/github/jan/supabase/realtime/RealtimeImpl.kt
index 6bed38ceb..2f641fb83 100644
--- a/Realtime/src/commonMain/kotlin/io/github/jan/supabase/realtime/RealtimeImpl.kt
+++ b/Realtime/src/commonMain/kotlin/io/github/jan/supabase/realtime/RealtimeImpl.kt
@@ -30,6 +30,8 @@ import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.isActive
 import kotlinx.coroutines.job
 import kotlinx.coroutines.launch
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
 import kotlinx.serialization.json.buildJsonObject
 
 internal class RealtimeImpl(override val supabaseClient: SupabaseClient, override val config: Realtime.Config) : Realtime {
@@ -41,6 +43,7 @@ internal class RealtimeImpl(override val supabaseClient: SupabaseClient, overrid
     override val subscriptions: Map<String, RealtimeChannel>
         get() = _subscriptions.toMap()
     private val scope = CoroutineScope(Dispatchers.Default + SupervisorJob())
+    private val mutex = Mutex()
     var heartbeatJob: Job? = null
     var messageJob: Job? = null
     var ref by atomic(0)
@@ -56,7 +59,7 @@ internal class RealtimeImpl(override val supabaseClient: SupabaseClient, overrid
 
     override suspend fun connect() = connect(false)
 
-    suspend fun connect(reconnect: Boolean) {
+    suspend fun connect(reconnect: Boolean): Unit = mutex.withLock {
         if (reconnect) {
             delay(config.reconnectDelay)
             Logger.d("Realtime") { "Reconnecting..." }