diff --git a/Mage.Client/src/main/java/mage/client/MageFrame.java b/Mage.Client/src/main/java/mage/client/MageFrame.java
index 0e1f02a3eb1..2cff98961e0 100644
--- a/Mage.Client/src/main/java/mage/client/MageFrame.java
+++ b/Mage.Client/src/main/java/mage/client/MageFrame.java
@@ -98,7 +98,7 @@ public class MageFrame extends javax.swing.JFrame implements MageClient {
     private static final String PASSWORD_ARG = "-pw";
     private static final String SERVER_ARG = "-server";
     private static final String PORT_ARG = "-port";
-    private static final String DEBUG_ARG = "-debug";
+    private static final String DEBUG_ARG = "-debug"; // enable debug button in main menu
 
     private static final String NOT_CONNECTED_TEXT = "<not connected>";
     private static final String NOT_CONNECTED_BUTTON = "CONNECT TO SERVER";
@@ -1327,6 +1327,10 @@ public class MageFrame extends javax.swing.JFrame implements MageClient {
                     debugMode = true;
                 }
             }
+
+            // enable debug menu by default for developer build (if you run it from source code)
+            debugMode |= VERSION.isDeveloperBuild();
+
             if (!liteMode) {
                 final SplashScreen splash = SplashScreen.getSplashScreen();
                 if (splash != null) {
diff --git a/Mage.Common/src/main/java/mage/utils/MageVersion.java b/Mage.Common/src/main/java/mage/utils/MageVersion.java
index 5d7ad75684b..afa4681102a 100644
--- a/Mage.Common/src/main/java/mage/utils/MageVersion.java
+++ b/Mage.Common/src/main/java/mage/utils/MageVersion.java
@@ -87,4 +87,8 @@ public class MageVersion implements Serializable, Comparable<MageVersion> {
         // all fine
         return 0;
     }
+
+    public boolean isDeveloperBuild() {
+        return this.buildTime.contains(JarVersion.JAR_BUILD_TIME_FROM_CLASSES);
+    }
 }
diff --git a/Mage.Server/src/main/java/mage/server/Main.java b/Mage.Server/src/main/java/mage/server/Main.java
index 2c967fb7d01..a96c22bad40 100644
--- a/Mage.Server/src/main/java/mage/server/Main.java
+++ b/Mage.Server/src/main/java/mage/server/Main.java
@@ -72,7 +72,7 @@ public final class Main {
     // - cheat commands;
     // - no deck validation;
     // - simplified registration and login (no password check);
-    // - debug main menu for GUI and rendering testing;
+    // - debug main menu for GUI and rendering testing (must use -debug arg for client app);
     private static boolean testMode;
 
     private static boolean fastDbMode;
@@ -88,12 +88,12 @@ public final class Main {
         String adminPassword = "";
         for (String arg : args) {
             if (arg.startsWith(testModeArg)) {
-                testMode = Boolean.valueOf(arg.replace(testModeArg, ""));
+                testMode = Boolean.parseBoolean(arg.replace(testModeArg, ""));
             } else if (arg.startsWith(adminPasswordArg)) {
                 adminPassword = arg.replace(adminPasswordArg, "");
                 adminPassword = SystemUtil.sanitize(adminPassword);
             } else if (arg.startsWith(fastDBModeArg)) {
-                fastDbMode = Boolean.valueOf(arg.replace(fastDBModeArg, ""));
+                fastDbMode = Boolean.parseBoolean(arg.replace(fastDBModeArg, ""));
             }
         }
 
diff --git a/Mage/src/main/java/mage/util/JarVersion.java b/Mage/src/main/java/mage/util/JarVersion.java
index 3089b441ab0..3e8786cd82a 100644
--- a/Mage/src/main/java/mage/util/JarVersion.java
+++ b/Mage/src/main/java/mage/util/JarVersion.java
@@ -15,7 +15,7 @@ import java.util.jar.Manifest;
 public class JarVersion {
 
     private static final Logger logger = Logger.getLogger(JarVersion.class);
-    private static final String JAR_BUILD_TIME_FROM_CLASSES = "runtime";
+    public static final String JAR_BUILD_TIME_FROM_CLASSES = "runtime";
     private static final String JAR_BUILD_TIME_ERROR = "n/a";
 
     public static String getBuildTime(Class clazz) {