diff --git a/java/com/google/gitiles/DiffServlet.java b/java/com/google/gitiles/DiffServlet.java
index 5b1801d..5a9f07b 100644
--- a/java/com/google/gitiles/DiffServlet.java
+++ b/java/com/google/gitiles/DiffServlet.java
@@ -152,7 +152,7 @@
     if (newCommit.getParentCount() > 0) {
       return Arrays.asList(newCommit.getParents()).contains(oldRevision.getId());
     }
-    return oldRevision == Revision.NULL;
+    return Revision.isNull(oldRevision);
   }
 
   private static boolean isFile(TreeWalk tw) {
diff --git a/java/com/google/gitiles/GitilesView.java b/java/com/google/gitiles/GitilesView.java
index 02020ee..e721c26 100644
--- a/java/com/google/gitiles/GitilesView.java
+++ b/java/com/google/gitiles/GitilesView.java
@@ -228,7 +228,7 @@
     public Builder setOldRevision(Revision revision) {
       if (type != Type.DIFF && type != Type.LOG) {
         revision = firstNonNull(revision, Revision.NULL);
-        checkState(revision == Revision.NULL, "cannot set old revision on %s view", type);
+        checkState(Revision.isNull(revision), "cannot set old revision on %s view", type);
       }
       this.oldRevision = revision;
       return this;
@@ -399,7 +399,7 @@
     }
 
     private void checkRevision() {
-      checkView(revision != Revision.NULL, "missing revision on %s view", type);
+      checkView(!Revision.isNull(revision), "missing revision on %s view", type);
       checkRepositoryIndex();
     }
 
@@ -427,7 +427,7 @@
     private void checkRootedDoc() {
       checkView(hostName != null, "missing hostName on %s view", type);
       checkView(servletPath != null, "missing hostName on %s view", type);
-      checkView(revision != Revision.NULL, "missing revision on %s view", type);
+      checkView(!Revision.isNull(revision), "missing revision on %s view", type);
       checkView(path != null, "missing path on %s view", type);
     }
   }
@@ -561,7 +561,7 @@
   }
 
   public String getRevisionRange() {
-    if (oldRevision == Revision.NULL) {
+    if (Revision.isNull(oldRevision)) {
       if (type == Type.LOG || type == Type.DIFF) {
         // For types that require two revisions, NULL indicates the empty
         // tree/commit.
@@ -676,9 +676,9 @@
         break;
       case LOG:
         url.append(repositoryName).append("/+log");
-        if (revision != Revision.NULL) {
+        if (!Revision.isNull(revision)) {
           url.append('/');
-          if (oldRevision != Revision.NULL) {
+          if (!Revision.isNull(oldRevision)) {
             url.append(oldRevision.getName()).append("..");
           }
           url.append(revision.getName());
@@ -764,10 +764,10 @@
       // separate links in "old..new".
       breadcrumbs.add(breadcrumb(getRevisionRange(), diff().copyFrom(this).setPathPart("")));
     } else if (type == Type.LOG) {
-      if (revision != Revision.NULL) {
+      if (!Revision.isNull(revision)) {
         // TODO(dborowitz): Add something in the navigation area (probably not
         // a breadcrumb) to allow switching between /+log/ and /+/.
-        if (oldRevision == Revision.NULL) {
+        if (Revision.isNull(oldRevision)) {
           breadcrumbs.add(breadcrumb(revision.getName(), log().copyFrom(this).setPathPart(null)));
         } else {
           breadcrumbs.add(breadcrumb(getRevisionRange(), log().copyFrom(this).setPathPart(null)));
@@ -776,7 +776,7 @@
         breadcrumbs.add(breadcrumb(Constants.HEAD, log().copyFrom(this)));
       }
       path = Strings.emptyToNull(path);
-    } else if (revision != Revision.NULL) {
+    } else if (!Revision.isNull(revision)) {
       breadcrumbs.add(breadcrumb(revision.getName(), revision().copyFrom(this)));
     }
     if (path != null) {
@@ -850,7 +850,7 @@
   }
 
   private static boolean isFirstParent(Revision rev1, Revision rev2) {
-    return rev2 == Revision.NULL
+    return Revision.isNull(rev2)
         || rev2.getName().equals(rev1.getName() + "^")
         || rev2.getName().equals(rev1.getName() + "~1");
   }
diff --git a/java/com/google/gitiles/LogServlet.java b/java/com/google/gitiles/LogServlet.java
index a91aeab..4d038ae 100644
--- a/java/com/google/gitiles/LogServlet.java
+++ b/java/com/google/gitiles/LogServlet.java
@@ -113,7 +113,7 @@
       }
 
       String title = "Log - ";
-      if (view.getOldRevision() != Revision.NULL) {
+      if (!Revision.isNull(view.getOldRevision())) {
         title += view.getRevisionRange();
       } else {
         title += view.getRevision().getName();
@@ -175,7 +175,7 @@
 
   private static GitilesView getView(HttpServletRequest req, Repository repo) throws IOException {
     GitilesView view = ViewFilter.getView(req);
-    if (view.getRevision() != Revision.NULL) {
+    if (!Revision.isNull(view.getRevision())) {
       return view;
     }
     Ref headRef = repo.exactRef(Constants.HEAD);
@@ -225,7 +225,7 @@
     RevWalk walk = new RevWalk(repo);
     try {
       walk.markStart(walk.parseCommit(view.getRevision().getId()));
-      if (view.getOldRevision() != Revision.NULL) {
+      if (!Revision.isNull(view.getOldRevision())) {
         walk.markUninteresting(walk.parseCommit(view.getOldRevision().getId()));
       }
     } catch (IncorrectObjectTypeException iote) {
diff --git a/java/com/google/gitiles/LogSoyData.java b/java/com/google/gitiles/LogSoyData.java
index 8bc243f..96ef6ae 100644
--- a/java/com/google/gitiles/LogSoyData.java
+++ b/java/com/google/gitiles/LogSoyData.java
@@ -176,14 +176,14 @@
   private GitilesView.Builder copyAndCanonicalizeView(String revision) {
     // Canonicalize the view by using full SHAs.
     GitilesView.Builder copy = GitilesView.log().copyFrom(view);
-    if (view.getRevision() != Revision.NULL) {
+    if (!Revision.isNull(view.getRevision())) {
       copy.setRevision(view.getRevision());
     } else if (revision != null) {
       copy.setRevision(Revision.named(revision));
     } else {
       copy.setRevision(Revision.NULL);
     }
-    if (view.getOldRevision() != Revision.NULL) {
+    if (!Revision.isNull(view.getOldRevision())) {
       copy.setOldRevision(view.getOldRevision());
     }
     return copy;
diff --git a/java/com/google/gitiles/Revision.java b/java/com/google/gitiles/Revision.java
index 3fc8d37..02a04f8 100644
--- a/java/com/google/gitiles/Revision.java
+++ b/java/com/google/gitiles/Revision.java
@@ -88,6 +88,11 @@
     this.peeledType = peeledType;
   }
 
+  @SuppressWarnings("ReferenceEquality")
+  public static boolean isNull(Revision r) {
+    return r == NULL;
+  }
+
   public String getName() {
     return name;
   }
diff --git a/java/com/google/gitiles/RevisionParser.java b/java/com/google/gitiles/RevisionParser.java
index 89311a3..d530cdd 100644
--- a/java/com/google/gitiles/RevisionParser.java
+++ b/java/com/google/gitiles/RevisionParser.java
@@ -225,7 +225,7 @@
     if (!cache.isVisible(repo, walk, access, id)) {
       return false;
     }
-    if (result.getOldRevision() != null && result.getOldRevision() != Revision.NULL) {
+    if (result.getOldRevision() != null && !Revision.isNull(result.getOldRevision())) {
       return cache.isVisible(repo, walk, access, result.getOldRevision().getId(), id);
     }
     return true;
diff --git a/java/com/google/gitiles/ViewFilter.java b/java/com/google/gitiles/ViewFilter.java
index f400ff0..2e517a1 100644
--- a/java/com/google/gitiles/ViewFilter.java
+++ b/java/com/google/gitiles/ViewFilter.java
@@ -119,7 +119,7 @@
   }
 
   private boolean normalize(GitilesView.Builder view, HttpServletResponse res) throws IOException {
-    if (view.getOldRevision() != Revision.NULL) {
+    if (!Revision.isNull(view.getOldRevision())) {
       return false;
     }
     Revision r = view.getRevision();