diff --git a/java/testFramework/src/com/intellij/testFramework/IdeaTestCase.java b/java/testFramework/src/com/intellij/testFramework/IdeaTestCase.java
index c5372661a182..abdb236f010b 100644
--- a/java/testFramework/src/com/intellij/testFramework/IdeaTestCase.java
+++ b/java/testFramework/src/com/intellij/testFramework/IdeaTestCase.java
@@ -43,11 +43,6 @@ public abstract class IdeaTestCase extends PlatformTestCase {
     super.tearDown();
   }
 
-  @SuppressWarnings({"JUnitTestCaseWithNonTrivialConstructors"})
-  protected IdeaTestCase() {
-    initPlatformPrefix();
-  }
-
   public final JavaPsiFacadeEx getJavaFacade() {
     return myJavaFacade;
   }
diff --git a/platform/testFramework/src/com/intellij/testFramework/PlatformTestCase.java b/platform/testFramework/src/com/intellij/testFramework/PlatformTestCase.java
index c7a3c088f4d3..a1f279e041cb 100644
--- a/platform/testFramework/src/com/intellij/testFramework/PlatformTestCase.java
+++ b/platform/testFramework/src/com/intellij/testFramework/PlatformTestCase.java
@@ -83,6 +83,7 @@ import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 import java.lang.reflect.InvocationTargetException;
+import java.net.URL;
 import java.util.Collection;
 import java.util.HashSet;
 import java.util.Set;
@@ -125,6 +126,7 @@ public abstract class PlatformTestCase extends UsefulTestCase implements DataPro
 
   protected void initApplication() throws Exception {
     boolean firstTime = ourApplication == null;
+    autodetectPlatformPrefix();
     ourApplication = IdeaTestApplication.getInstance(getApplicationConfigDirPath());
     ourApplication.setDataProvider(this);
 
@@ -133,6 +135,22 @@ public abstract class PlatformTestCase extends UsefulTestCase implements DataPro
     }
   }
 
+  private static void autodetectPlatformPrefix() {
+    if (ourPlatformPrefixInitialized) {
+      return;
+    }
+    URL resource = PlatformTestCase.class.getClassLoader().getResource("idea/ApplicationInfo.xml");
+    if (resource == null) {
+      resource = PlatformTestCase.class.getClassLoader().getResource("idea/IdeaApplicationInfo.xml");
+      if (resource == null) {
+        System.setProperty("idea.platform.prefix", "PlatformLangXml");
+      }
+      else {
+        System.setProperty("idea.platform.prefix", "Idea");
+      }
+    }
+  }
+
   private static void cleanPersistedVFSContent() {
     ((PersistentFS)ManagingFS.getInstance()).cleanPersistedContents();
   }