diff --git a/plugins/git4idea/src/git4idea/GitRootConverter.java b/plugins/git4idea/src/git4idea/GitRootConverter.java
index 1e29fde47f51..0250524bcaf5 100644
--- a/plugins/git4idea/src/git4idea/GitRootConverter.java
+++ b/plugins/git4idea/src/git4idea/GitRootConverter.java
@@ -16,13 +16,9 @@
 
 package git4idea;
 
-import com.intellij.openapi.project.Project;
 import com.intellij.openapi.vcs.AbstractVcs;
-import com.intellij.openapi.vcs.VcsDirectoryMapping;
 import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.util.containers.HashSet;
-import git4idea.roots.GitRootDetectInfo;
-import git4idea.roots.GitRootDetector;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.ArrayList;
@@ -33,23 +29,12 @@ import java.util.List;
  */
 public class GitRootConverter implements AbstractVcs.RootsConvertor {
 
-  @NotNull private final Project myProject;
-  @NotNull private final PlatformFacade myPlatformFacade;
-
-  public GitRootConverter(@NotNull Project project, @NotNull PlatformFacade facade) {
-    myProject = project;
-    myPlatformFacade = facade;
-  }
+  public static final GitRootConverter INSTANCE = new GitRootConverter();
 
   @NotNull
   public List<VirtualFile> convertRoots(@NotNull List<VirtualFile> result) {
-    GitRootDetectInfo detectInfo = new GitRootDetector(myProject, myPlatformFacade).detect();
-
+    // TODO this should be faster, because it is called rather often. gitRootOrNull could be a bottle-neck.
     ArrayList<VirtualFile> roots = new ArrayList<VirtualFile>();
-    if (hasProjectMapping()) {
-      roots.addAll(detectInfo.getRoots());
-    }
-
     HashSet<VirtualFile> listed = new HashSet<VirtualFile>();
     for (VirtualFile f : result) {
       VirtualFile r = GitUtil.gitRootOrNull(f);
@@ -59,14 +44,4 @@ public class GitRootConverter implements AbstractVcs.RootsConvertor {
     }
     return roots;
   }
-
-  private boolean hasProjectMapping() {
-    for (VcsDirectoryMapping mapping : myPlatformFacade.getVcsManager(myProject).getDirectoryMappings()) {
-      if (mapping.isDefaultMapping()) {
-        return true;
-      }
-    }
-    return false;
-  }
-
 }
diff --git a/plugins/git4idea/src/git4idea/GitVcs.java b/plugins/git4idea/src/git4idea/GitVcs.java
index 6f4e778b7655..8bee54c341f3 100644
--- a/plugins/git4idea/src/git4idea/GitVcs.java
+++ b/plugins/git4idea/src/git4idea/GitVcs.java
@@ -135,7 +135,6 @@ public class GitVcs extends AbstractVcs<CommittedChangeList> {
   private GitBranchWidget myBranchWidget;
 
   private GitVersion myVersion = GitVersion.NULL; // version of Git which this plugin uses.
-  private final GitRootConverter myRootConverter;
 
   @Nullable
   public static GitVcs getInstance(Project project) {
@@ -175,7 +174,6 @@ public class GitVcs extends AbstractVcs<CommittedChangeList> {
     myTaskQueue = new BackgroundTaskQueue(myProject, GitBundle.getString("task.queue.title"));
     myExecutableValidator = new GitExecutableValidator(myProject, this);
     myPlatformFacade = ServiceManager.getService(myProject, PlatformFacade.class);
-    myRootConverter = new GitRootConverter(myProject, myPlatformFacade);
   }
 
 
@@ -497,7 +495,7 @@ public class GitVcs extends AbstractVcs<CommittedChangeList> {
 
   @Override
   public RootsConvertor getCustomConvertor() {
-    return myRootConverter;
+    return GitRootConverter.INSTANCE;
   }
 
   public static VcsKey getKey() {
diff --git a/plugins/git4idea/src/git4idea/roots/GitRootErrorsFinder.java b/plugins/git4idea/src/git4idea/roots/GitRootErrorsFinder.java
index 8f68c17ef72f..8f03a93e0d0f 100644
--- a/plugins/git4idea/src/git4idea/roots/GitRootErrorsFinder.java
+++ b/plugins/git4idea/src/git4idea/roots/GitRootErrorsFinder.java
@@ -25,6 +25,7 @@ import git4idea.PlatformFacade;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.List;
 
@@ -53,21 +54,17 @@ public class GitRootErrorsFinder {
     Collection<VirtualFile> gitRoots = new GitRootDetector(myProject, myPlatformFacade).detect().getRoots();
 
     Collection<VcsRootError> errors = new ArrayList<VcsRootError>();
-    Collection<String> gitPaths = rootsToPaths(gitRoots);
-    errors.addAll(findExtraMappings(mappings, gitPaths));
-    errors.addAll(findUnregisteredRoots(mappings, gitPaths));
+    errors.addAll(findExtraMappings(mappings, rootsToPaths(gitRoots)));
+    errors.addAll(findUnregisteredRoots(gitRoots));
     return errors;
   }
 
-  private Collection<VcsRootError> findUnregisteredRoots(List<VcsDirectoryMapping> mappings, Collection<String> gitPaths) {
+  private Collection<VcsRootError> findUnregisteredRoots(Collection<VirtualFile> gitRoots) {
     Collection<VcsRootError> errors = new ArrayList<VcsRootError>();
-    if (hasProjectMapping(myPlatformFacade.getVcsManager(myProject).getDirectoryMappings())) {
-      return errors;
-    }
-    List<String> mappedPaths = mappingsToPaths(mappings);
-    for (String gitPath : gitPaths) {
-      if (!mappedPaths.contains(gitPath)) {
-        errors.add(new VcsRootError(VcsRootError.Type.UNREGISTERED_ROOT, gitPath));
+    Collection<VirtualFile> vcsRoots = Arrays.asList(myVcsManager.getRootsUnderVcs(myVcs));
+    for (VirtualFile gitRoot : gitRoots) {
+      if (!vcsRoots.contains(gitRoot)) {
+        errors.add(new VcsRootError(VcsRootError.Type.UNREGISTERED_ROOT, gitRoot.getPath()));
       }
     }
     return errors;
@@ -100,23 +97,4 @@ public class GitRootErrorsFinder {
     return gitPaths;
   }
 
-  private static List<String> mappingsToPaths(List<VcsDirectoryMapping> mappings) {
-    List<String> paths = new ArrayList<String>();
-    for (VcsDirectoryMapping mapping : mappings) {
-      if (!mapping.isDefaultMapping()) {
-        paths.add(mapping.systemIndependentPath());
-      }
-    }
-    return paths;
-  }
-
-  private static boolean hasProjectMapping(List<VcsDirectoryMapping> mappings) {
-    for (VcsDirectoryMapping mapping : mappings) {
-      if (mapping.isDefaultMapping()) {
-        return true;
-      }
-    }
-    return false;
-  }
-
 }
diff --git a/plugins/git4idea/tests/git4idea/roots/GitRootErrorsFinderTest.groovy b/plugins/git4idea/tests/git4idea/roots/GitRootErrorsFinderTest.groovy
index cf002e7a74b6..f40b1a590cda 100644
--- a/plugins/git4idea/tests/git4idea/roots/GitRootErrorsFinderTest.groovy
+++ b/plugins/git4idea/tests/git4idea/roots/GitRootErrorsFinderTest.groovy
@@ -131,19 +131,20 @@ class GitRootErrorsFinderTest extends AbstractGitRootTest {
   }
   
   @Test
-  void "Project root, git below project folder not in a content root, then correct since folders are auto-detected"() {
+  void "Project root, git below project folder not in a content root, then unregistered root error"() {
+  // this is to be fixed: auto-detection of Git repositories in subfolders for the <Project> mapping
     doTest content_roots: ["."],
            git:    ["community"],
            roots:  [PROJECT],
-           errors: []
+           errors: [unreg: ["community"]]
   }
 
   @Test
-  void "Project root, git for full project, content root, linked source, folder below project, then correct since folders are detected"() {
+  void "Project root, git for full project, content root, linked source, folder below project, then error in folder below"() {
     doTest content_roots: [".", "content_root", "../linked_source_root"],
            git:           [".", "content_root", "../linked_source_root", "folder"],
            roots:         [PROJECT],
-           errors:        []
+           errors:        [unreg: ["folder"]]
   }
 
   @Test
diff --git a/plugins/git4idea/tests/git4idea/test/GitMockVcsManager.groovy b/plugins/git4idea/tests/git4idea/test/GitMockVcsManager.groovy
index 779ba4173494..4486690c47f2 100644
--- a/plugins/git4idea/tests/git4idea/test/GitMockVcsManager.groovy
+++ b/plugins/git4idea/tests/git4idea/test/GitMockVcsManager.groovy
@@ -57,7 +57,6 @@ public class GitMockVcsManager extends ProjectLevelVcsManager {
     List<VirtualFile> roots = myRoots.collect { new GitMockVirtualFile(it) }
     roots.addAll(myPlatformFacade.getProjectRootManager(myProject).getContentRoots())
     roots
-//     new GitRootConverter(myProject, myPlatformFacade).convertRoots(roots)
   }
 
   @Override