diff --git a/Assets/Mirror/Components/Discovery/NetworkDiscoveryBase.cs b/Assets/Mirror/Components/Discovery/NetworkDiscoveryBase.cs
index daf4137c1..c55c1ebb4 100644
--- a/Assets/Mirror/Components/Discovery/NetworkDiscoveryBase.cs
+++ b/Assets/Mirror/Components/Discovery/NetworkDiscoveryBase.cs
@@ -62,11 +62,10 @@ public static long RandomLong()
         /// </summary>
         public virtual void Start()
         {
-            // headless mode? then start advertising
-            if (NetworkManager.isHeadless)
-            {
-                AdvertiseServer();
-            }
+            // Server mode? then start advertising
+#if UNITY_SERVER
+            AdvertiseServer();
+#endif
         }
 
         // Ensure the ports are cleared no matter when Game/Unity UI exits
diff --git a/Assets/Mirror/Examples/Room/Scripts/NetworkRoomManagerExt.cs b/Assets/Mirror/Examples/Room/Scripts/NetworkRoomManagerExt.cs
index bce48460f..6313609ed 100644
--- a/Assets/Mirror/Examples/Room/Scripts/NetworkRoomManagerExt.cs
+++ b/Assets/Mirror/Examples/Room/Scripts/NetworkRoomManagerExt.cs
@@ -55,10 +55,11 @@ Setting showStartButton false when the button is pressed hides it in the game sc
         public override void OnRoomServerPlayersReady()
         {
             // calling the base method calls ServerChangeScene as soon as all players are in Ready state.
-            if (isHeadless)
-                base.OnRoomServerPlayersReady();
-            else
-                showStartButton = true;
+#if UNITY_SERVER
+            base.OnRoomServerPlayersReady();
+#else
+            showStartButton = true;
+#endif
         }
 
         public override void OnGUI()
diff --git a/Assets/Mirror/Runtime/Logging/NetworkHeadlessLogger.cs b/Assets/Mirror/Runtime/Logging/NetworkHeadlessLogger.cs
index d41bc2e06..a6e85b68d 100644
--- a/Assets/Mirror/Runtime/Logging/NetworkHeadlessLogger.cs
+++ b/Assets/Mirror/Runtime/Logging/NetworkHeadlessLogger.cs
@@ -14,10 +14,9 @@ public class NetworkHeadlessLogger : MonoBehaviour
 
         void Awake()
         {
-            if (NetworkManager.isHeadless)
-            {
-                LogFactory.ReplaceLogHandler(new ConsoleColorLogHandler(showExceptionStackTrace));
-            }
+#if UNITY_SERVER
+            LogFactory.ReplaceLogHandler(new ConsoleColorLogHandler(showExceptionStackTrace));
+#endif
         }
     }
 }
diff --git a/Assets/Mirror/Runtime/NetworkManager.cs b/Assets/Mirror/Runtime/NetworkManager.cs
index 36d147914..99cb95ae7 100644
--- a/Assets/Mirror/Runtime/NetworkManager.cs
+++ b/Assets/Mirror/Runtime/NetworkManager.cs
@@ -45,10 +45,15 @@ public class NetworkManager : MonoBehaviour
 
         /// <summary>
         /// Automatically invoke StartServer()
-        /// <para>If the application is a Server Build or run with the -batchMode command line arguement, StartServer is automatically invoked.</para>
+        /// <para>If the application is a Server Build, StartServer is automatically invoked.</para>
+        /// <para>Server build is true when "Server build" is checked in build menu, or BuildOptions.EnableHeadlessMode flag is in BuildOptions</para>	
         /// </summary>
-        [Tooltip("Should the server auto-start when the game is started in a headless build?")]
-        public bool startOnHeadless = true;
+        [Tooltip("Should the server auto-start when 'Server Build' is checked in build settings")]
+        [FormerlySerializedAs("startOnHeadless")]
+        public bool autoStartServerBuild = true;
+
+        [Obsolete("Use autoStartServerBuild instead.")]
+        public bool startOnHeadless { get => autoStartServerBuild; set => autoStartServerBuild = value; }
 
         /// <summary>
         /// Enables verbose debug messages in the console
@@ -185,6 +190,7 @@ public class NetworkManager : MonoBehaviour
         /// <summary>
         /// headless mode detection
         /// </summary>
+        [Obsolete("Use #if UNITY_SERVER instead.")]
         public static bool isHeadless => SystemInfo.graphicsDeviceType == GraphicsDeviceType.Null;
 
         // helper enum to know if we started the networkmanager as server/client/host.
@@ -255,10 +261,12 @@ public virtual void Start()
             // some transports might not be ready until Start.
             //
             // (tick rate is applied in StartServer!)
-            if (isHeadless && startOnHeadless)
+#if UNITY_SERVER
+            if (autoStartServerBuild)
             {
                 StartServer();
             }
+#endif
         }
 
         // NetworkIdentity.UNetStaticUpdate is called from UnityEngine while LLAPI network is active.
@@ -675,15 +683,10 @@ public virtual void OnApplicationQuit()
         /// </summary>
         public virtual void ConfigureServerFrameRate()
         {
-            // set a fixed tick rate instead of updating as often as possible
-            // * if not in Editor (it doesn't work in the Editor)
-            // * if not in Host mode
-#if !UNITY_EDITOR
-            if (!NetworkClient.active && isHeadless)
-            {
-                Application.targetFrameRate = serverTickRate;
-                if (logger.logEnabled) logger.Log("Server Tick Rate set to: " + Application.targetFrameRate + " Hz.");
-            }
+            // only set framerate for server build
+#if UNITY_SERVER
+            Application.targetFrameRate = serverTickRate;
+            if (logger.logEnabled) logger.Log("Server Tick Rate set to: " + Application.targetFrameRate + " Hz.");
 #endif
         }
 
diff --git a/Assets/Mirror/Tests/Editor/NetworkManagerTest.cs b/Assets/Mirror/Tests/Editor/NetworkManagerTest.cs
index d88705ec4..11f73a852 100644
--- a/Assets/Mirror/Tests/Editor/NetworkManagerTest.cs
+++ b/Assets/Mirror/Tests/Editor/NetworkManagerTest.cs
@@ -29,7 +29,7 @@ public void VariableTest()
         {
             Assert.That(manager.dontDestroyOnLoad, Is.True);
             Assert.That(manager.runInBackground, Is.True);
-            Assert.That(manager.startOnHeadless, Is.True);
+            Assert.That(manager.autoStartServerBuild, Is.True);
             Assert.That(manager.showDebugMessages, Is.False);
             Assert.That(manager.serverTickRate, Is.EqualTo(30));
             Assert.That(manager.offlineScene, Is.Empty);
diff --git a/Assets/Mirror/Tests/Runtime/HostSetup.cs b/Assets/Mirror/Tests/Runtime/HostSetup.cs
index a72cb660b..2871f703d 100644
--- a/Assets/Mirror/Tests/Runtime/HostSetup.cs
+++ b/Assets/Mirror/Tests/Runtime/HostSetup.cs
@@ -27,7 +27,7 @@ public IEnumerator SetupHost()
             identity.assetId = System.Guid.NewGuid();
 
             manager.playerPrefab = playerGO;
-            manager.startOnHeadless = false;
+            manager.autoStartServerBuild = false;
 
             yield return null;