diff --git a/platform/lang-impl/src/com/intellij/openapi/fileTypes/FileTypeUsagesCollector.java b/platform/lang-impl/src/com/intellij/openapi/fileTypes/FileTypeUsagesCollector.java
index a414907b5ec2..b2eac02b3541 100644
--- a/platform/lang-impl/src/com/intellij/openapi/fileTypes/FileTypeUsagesCollector.java
+++ b/platform/lang-impl/src/com/intellij/openapi/fileTypes/FileTypeUsagesCollector.java
@@ -58,7 +58,8 @@ public class FileTypeUsagesCollector extends AbstractApplicationUsagesCollector
       if (project.isDisposed()) {
         throw new CollectUsagesException("Project is disposed");
       }
-      final String ideaDirPath = project.getBaseDir().findChild(Project.DIRECTORY_STORE_FOLDER).getPath();
+      VirtualFile ideaDir = project.getBaseDir().findChild(Project.DIRECTORY_STORE_FOLDER);
+      final String ideaDirPath = ideaDir == null ? null : ideaDir.getPath();
       ApplicationManager.getApplication().runReadAction(new Runnable() {
         @Override
         public void run() {
@@ -70,7 +71,7 @@ public class FileTypeUsagesCollector extends AbstractApplicationUsagesCollector
               @Override
               public boolean process(VirtualFile file, Void value) {
                 //skip files from .idea directory otherwise 99% of projects would have XML and PLAIN_TEXT file types
-                if (!file.getPath().startsWith(ideaDirPath)) {
+                if (ideaDirPath == null || !file.getPath().startsWith(ideaDirPath)) {
                   usedFileTypes.add(fileType);
                   return false;
                 }
diff --git a/platform/platform-tests/testSrc/com/intellij/openapi/fileTypes/FileTypeUsagesCollectorTest.java b/platform/platform-tests/testSrc/com/intellij/openapi/fileTypes/FileTypeUsagesCollectorTest.java
index 48368840cc44..2f11676d7df7 100644
--- a/platform/platform-tests/testSrc/com/intellij/openapi/fileTypes/FileTypeUsagesCollectorTest.java
+++ b/platform/platform-tests/testSrc/com/intellij/openapi/fileTypes/FileTypeUsagesCollectorTest.java
@@ -55,17 +55,17 @@ public class FileTypeUsagesCollectorTest extends LightPlatformCodeInsightFixture
   }
 
   public void testEmptyProject() throws CollectUsagesException {
-    doTest(Arrays.asList(UnknownFileType.INSTANCE));
+    doTest(Arrays.asList());
   }
 
   public void testSingleFileProject() throws CollectUsagesException {
     myFixture.configureByText("a.txt", "");
-    doTest(Arrays.asList(UnknownFileType.INSTANCE, PlainTextFileType.INSTANCE));
+    doTest(Arrays.asList(PlainTextFileType.INSTANCE));
   }
 
   public void testSeveralSameFilesProject() throws CollectUsagesException {
     myFixture.configureByText("a.txt", "");
     myFixture.configureByText("b.txt", "");
-    doTest(Arrays.asList(UnknownFileType.INSTANCE, PlainTextFileType.INSTANCE));
+    doTest(Arrays.asList(PlainTextFileType.INSTANCE));
   }
 }