diff --git a/Mage.Server/src/main/java/mage/server/Main.java b/Mage.Server/src/main/java/mage/server/Main.java
index a96c22bad40..11309c465d5 100644
--- a/Mage.Server/src/main/java/mage/server/Main.java
+++ b/Mage.Server/src/main/java/mage/server/Main.java
@@ -97,6 +97,9 @@ public final class Main {
             }
         }
 
+        // enable test mode by default for developer build (if you run it from source code)
+        testMode |= version.isDeveloperBuild();
+
         final String configPath = Optional.ofNullable(System.getProperty(configPathProp))
                 .orElse(defaultConfigPath);