diff --git a/apps/android/app/src/main/assets/www/call.js b/apps/android/app/src/main/assets/www/call.js
index 7267b0ba35..4c331cc539 100644
--- a/apps/android/app/src/main/assets/www/call.js
+++ b/apps/android/app/src/main/assets/www/call.js
@@ -25,8 +25,8 @@ let activeCall;
 let answerTimeout = 30000;
 const processCommand = (function () {
     const defaultIceServers = [
-        { urls: ["stun:stun.simplex.im:443"] },
-        { urls: ["turn:turn.simplex.im:443"], username: "private", credential: "yleob6AVkiNI87hpR94Z" },
+        { urls: ["stun:stun.simplex.im:443?transport=tcp"] },
+        { urls: ["turn:turn.simplex.im:443?transport=tcp"], username: "private", credential: "yleob6AVkiNI87hpR94Z" },
     ];
     function getCallConfig(encodedInsertableStreams, iceServers, relay) {
         return {
diff --git a/apps/android/app/src/main/java/chat/simplex/app/views/call/WebRTC.kt b/apps/android/app/src/main/java/chat/simplex/app/views/call/WebRTC.kt
index 7f850a35d1..93b3bd8a6f 100644
--- a/apps/android/app/src/main/java/chat/simplex/app/views/call/WebRTC.kt
+++ b/apps/android/app/src/main/java/chat/simplex/app/views/call/WebRTC.kt
@@ -1,9 +1,9 @@
 package chat.simplex.app.views.call
 
+import android.util.Log
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.res.stringResource
-import chat.simplex.app.R
-import chat.simplex.app.SimplexApp
+import chat.simplex.app.*
 import chat.simplex.app.model.Contact
 import chat.simplex.app.model.User
 import chat.simplex.app.views.helpers.generalGetString
@@ -159,8 +159,8 @@ data class ConnectionState(
 )
 
 // the servers are expected in this format:
-// stun:stun.simplex.im:443
-// turn:private:yleob6AVkiNI87hpR94Z@turn.simplex.im:443
+// stun:stun.simplex.im:443?transport=tcp
+// turn:private:yleob6AVkiNI87hpR94Z@turn.simplex.im:443?transport=tcp
 fun parseRTCIceServer(str: String): RTCIceServer? {
   var s = replaceScheme(str, "stun:")
   s = replaceScheme(s, "turn:")
@@ -171,8 +171,9 @@ fun parseRTCIceServer(str: String): RTCIceServer? {
     val port = u.port
     if (u.path == "" && (scheme == "stun" || scheme == "turn")) {
       val userInfo = u.userInfo?.split(":")
+      val query = if (u.query == null || u.query == "") "" else "?${u.query}"
       return RTCIceServer(
-        urls = listOf("$scheme:$host:$port"),
+        urls = listOf("$scheme:$host:$port$query"),
         username = userInfo?.getOrNull(0),
         credential = userInfo?.getOrNull(1)
       )
diff --git a/apps/ios/Shared/Views/Call/WebRTC.swift b/apps/ios/Shared/Views/Call/WebRTC.swift
index 930410af97..e74d05d643 100644
--- a/apps/ios/Shared/Views/Call/WebRTC.swift
+++ b/apps/ios/Shared/Views/Call/WebRTC.swift
@@ -396,8 +396,8 @@ struct RTCIceServer: Codable, Equatable {
 }
 
 // the servers are expected in this format:
-// stun:stun.simplex.im:443
-// turn:private:yleob6AVkiNI87hpR94Z@turn.simplex.im:443
+// stun:stun.simplex.im:443?transport=tcp
+// turn:private:yleob6AVkiNI87hpR94Z@turn.simplex.im:443?transport=tcp
 func parseRTCIceServer(_ str: String) -> RTCIceServer? {
     var s = replaceScheme(str, "stun:")
     s = replaceScheme(s, "turn:")
@@ -406,8 +406,9 @@ func parseRTCIceServer(_ str: String) -> RTCIceServer? {
        let host = u.host,
        let port = u.port,
        u.path == "" && (scheme == "stun" || scheme == "turn")  {
+        let query = u.query == nil || u.query == "" ? "" : "?" + (u.query ?? "")
         return RTCIceServer(
-            urls: ["\(scheme):\(host):\(port)"],
+            urls: ["\(scheme):\(host):\(port)\(query)"],
             username: u.user,
             credential: u.password
         )
diff --git a/packages/simplex-chat-webrtc/src/call.ts b/packages/simplex-chat-webrtc/src/call.ts
index ec1691c8d1..773280ec79 100644
--- a/packages/simplex-chat-webrtc/src/call.ts
+++ b/packages/simplex-chat-webrtc/src/call.ts
@@ -218,8 +218,8 @@ const processCommand = (function () {
   }
 
   const defaultIceServers: RTCIceServer[] = [
-    {urls: ["stun:stun.simplex.im:443"]},
-    {urls: ["turn:turn.simplex.im:443"], username: "private", credential: "yleob6AVkiNI87hpR94Z"},
+    {urls: ["stun:stun.simplex.im:443?transport=tcp"]},
+    {urls: ["turn:turn.simplex.im:443?transport=tcp"], username: "private", credential: "yleob6AVkiNI87hpR94Z"},
   ]
 
   function getCallConfig(encodedInsertableStreams: boolean, iceServers?: RTCIceServer[], relay?: boolean): CallConfig {