diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/junit/TestRepositoryTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/junit/TestRepositoryTest.java
index 8b54dabce..b7027f327 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/junit/TestRepositoryTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/junit/TestRepositoryTest.java
@@ -62,6 +62,7 @@
 import org.eclipse.jgit.lib.ObjectLoader;
 import org.eclipse.jgit.lib.PersonIdent;
 import org.eclipse.jgit.lib.Ref;
+import org.eclipse.jgit.lib.RefUpdate;
 import org.eclipse.jgit.revwalk.RevBlob;
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.revwalk.RevObject;
@@ -374,6 +375,44 @@ public void cherryPickWithIdenticalContents() throws Exception {
 		assertEquals(head, repo.exactRef("HEAD").getObjectId());
 	}
 
+	@Test
+	public void reattachToMaster_Race() throws Exception {
+		RevCommit commit = tr.branch("master").commit().create();
+		tr.branch("master").update(commit);
+		tr.branch("other").update(commit);
+		repo.updateRef("HEAD").link("refs/heads/master");
+
+		// Create a detached HEAD that is not an .
+		tr.reset(commit);
+		Ref head = repo.exactRef("HEAD");
+		assertEquals(commit, head.getObjectId());
+		assertFalse(head.isSymbolic());
+
+		// Try to reattach to master.
+		RefUpdate refUpdate = repo.updateRef("HEAD");
+
+		// Make a change during reattachment.
+		repo.updateRef("HEAD").link("refs/heads/other");
+
+		assertEquals(
+				RefUpdate.Result.LOCK_FAILURE, refUpdate.link("refs/heads/master"));
+	}
+
+	@Test
+	public void nonRacingChange() throws Exception {
+		tr.branch("master").update(tr.branch("master").commit().create());
+		tr.branch("other").update(tr.branch("other").commit().create());
+		repo.updateRef("HEAD").link("refs/heads/master");
+
+		// Try to update HEAD.
+		RefUpdate refUpdate = repo.updateRef("HEAD");
+
+		// Proceed a master. This should not affect changing HEAD.
+		tr.branch("master").update(tr.branch("master").commit().create());
+
+		assertEquals(RefUpdate.Result.FORCED, refUpdate.link("refs/heads/other"));
+	}
+
 	private String blobAsString(AnyObjectId treeish, String path)
 			throws Exception {
 		RevObject obj = tr.get(rw.parseTree(treeish), path);
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsRefDatabase.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsRefDatabase.java
index 5611d23be..4ddcec167 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsRefDatabase.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsRefDatabase.java
@@ -311,6 +311,15 @@ private RefCache read() throws IOException {
 
 	/**
 	 * Compare a reference, and put if it matches.
+	 * <p>
+	 * Two reference match if and only if they satisfy the following:
+	 *
+	 * <ul>
+	 * <li>If one reference is a symbolic ref, the other one should be a symbolic
+	 * ref.
+	 * <li>If both are symbolic refs, the target names should be same.
+	 * <li>If both are object ID refs, the object IDs should be same.
+	 * </ul>
 	 *
 	 * @param oldRef
 	 *            old value to compare to. If the reference is expected to not
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/InMemoryRepository.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/InMemoryRepository.java
index 2e1c90d3c..6f390a4b3 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/InMemoryRepository.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/InMemoryRepository.java
@@ -24,7 +24,6 @@
 import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.Ref.Storage;
 import org.eclipse.jgit.lib.RefDatabase;
-import org.eclipse.jgit.lib.SymbolicRef;
 import org.eclipse.jgit.revwalk.RevObject;
 import org.eclipse.jgit.revwalk.RevTag;
 import org.eclipse.jgit.revwalk.RevWalk;
@@ -401,27 +400,8 @@ protected boolean compareAndPut(Ref oldRef, Ref newRef)
 					return refs.putIfAbsent(name, newRef) == null;
 
 				Ref cur = refs.get(name);
-				Ref toCompare = cur;
-				if (toCompare != null) {
-					if (toCompare.isSymbolic()) {
-						// Arm's-length dereference symrefs before the compare, since
-						// DfsRefUpdate#doLink(String) stores them undereferenced.
-						Ref leaf = toCompare.getLeaf();
-						if (leaf.getObjectId() == null) {
-							leaf = refs.get(leaf.getName());
-							if (leaf.isSymbolic())
-								// Not supported at the moment.
-								throw new IllegalArgumentException();
-							toCompare = new SymbolicRef(
-									name,
-									new ObjectIdRef.Unpeeled(
-											Storage.NEW,
-											leaf.getName(),
-											leaf.getObjectId()));
-						} else
-							toCompare = toCompare.getLeaf();
-					}
-					if (eq(toCompare, oldRef))
+				if (cur != null) {
+					if (eq(cur, oldRef))
 						return refs.replace(name, cur, newRef);
 				}
 
@@ -452,10 +432,12 @@ protected boolean compareAndRemove(Ref oldRef) throws IOException {
 		private boolean eq(Ref a, Ref b) {
 			if (!Objects.equals(a.getName(), b.getName()))
 				return false;
-			// Compare leaf object IDs, since the oldRef passed into compareAndPut
-			// when detaching a symref is an ObjectIdRef.
-			return Objects.equals(a.getLeaf().getObjectId(),
-					b.getLeaf().getObjectId());
+			if (a.isSymbolic() != b.isSymbolic())
+				return false;
+			if (a.isSymbolic())
+				return Objects.equals(a.getTarget().getName(), b.getTarget().getName());
+			else
+				return Objects.equals(a.getObjectId(), b.getObjectId());
 		}
 	}
 }