diff --git a/gitiles-servlet/src/main/java/com/google/gitiles/GitilesView.java b/gitiles-servlet/src/main/java/com/google/gitiles/GitilesView.java
index fc553c7..d3bf7cf 100644
--- a/gitiles-servlet/src/main/java/com/google/gitiles/GitilesView.java
+++ b/gitiles-servlet/src/main/java/com/google/gitiles/GitilesView.java
@@ -196,7 +196,8 @@
         case LOG:
           break;
         default:
-          checkState(revision == null, "cannot set old revision on %s view", type);
+          revision = Objects.firstNonNull(revision, Revision.NULL);
+          checkState(revision == Revision.NULL, "cannot set old revision on %s view", type);
           break;
       }
       this.oldRevision = revision;
@@ -212,7 +213,7 @@
     }
 
     public Revision getOldRevision() {
-      return revision;
+      return oldRevision;
     }
 
     public Builder setPathPart(String path) {
diff --git a/gitiles-servlet/src/main/java/com/google/gitiles/Revision.java b/gitiles-servlet/src/main/java/com/google/gitiles/Revision.java
index 3fdf777..a93d4b5 100644
--- a/gitiles-servlet/src/main/java/com/google/gitiles/Revision.java
+++ b/gitiles-servlet/src/main/java/com/google/gitiles/Revision.java
@@ -43,6 +43,14 @@
   /** Common default branch given to clients. */
   public static final Revision HEAD = named("HEAD");
 
+  public static Revision normalizeParentExpressions(Revision rev) {
+    if (rev == null
+        || (rev.name.indexOf("~") < 0 && rev.name.indexOf("^") < 0)) {
+      return rev;
+    }
+    return new Revision(rev.id.name(), rev.id, rev.type, rev.peeledId, rev.peeledType);
+  }
+
   private final String name;
   private final ObjectId id;
   private final int type;
diff --git a/gitiles-servlet/src/main/java/com/google/gitiles/ViewFilter.java b/gitiles-servlet/src/main/java/com/google/gitiles/ViewFilter.java
index 13537dc..e8b1055 100644
--- a/gitiles-servlet/src/main/java/com/google/gitiles/ViewFilter.java
+++ b/gitiles-servlet/src/main/java/com/google/gitiles/ViewFilter.java
@@ -106,11 +106,16 @@
       res.setStatus(SC_NOT_FOUND);
       return;
     }
+
     @SuppressWarnings("unchecked")
     Map<String, String[]> params = req.getParameterMap();
     view.setHostName(urls.getHostName(req))
         .setServletPath(req.getContextPath() + req.getServletPath())
         .putAllParams(params);
+    if (normalize(view, res)) {
+      return;
+    }
+
     setView(req, view.build());
     try {
       chain.doFilter(req, res);
@@ -119,6 +124,20 @@
     }
   }
 
+  private boolean normalize(GitilesView.Builder view, HttpServletResponse res)
+      throws IOException {
+    if (view.getOldRevision() != Revision.NULL) {
+      return false;
+    }
+    Revision r = view.getRevision();
+    Revision nr = Revision.normalizeParentExpressions(r);
+    if (r != nr) {
+      res.sendRedirect(view.setRevision(nr).toUrl());
+      return true;
+    }
+    return false;
+  }
+
   private GitilesView.Builder parse(HttpServletRequest req) throws IOException {
     String repoName = trimLeadingSlash(getRegexGroup(req, 1));
     if (repoName.isEmpty()) {
diff --git a/gitiles-servlet/src/test/java/com/google/gitiles/FakeHttpServletResponse.java b/gitiles-servlet/src/test/java/com/google/gitiles/FakeHttpServletResponse.java
index 85da54f..558eb4c 100644
--- a/gitiles-servlet/src/test/java/com/google/gitiles/FakeHttpServletResponse.java
+++ b/gitiles-servlet/src/test/java/com/google/gitiles/FakeHttpServletResponse.java
@@ -208,8 +208,9 @@
   }
 
   @Override
-  public synchronized void sendRedirect(String msg) {
+  public synchronized void sendRedirect(String loc) {
     status = SC_FOUND;
+    setHeader(HttpHeaders.LOCATION, loc);
     committed = true;
   }
 
diff --git a/gitiles-servlet/src/test/java/com/google/gitiles/ViewFilterTest.java b/gitiles-servlet/src/test/java/com/google/gitiles/ViewFilterTest.java
index 4e80c39..2660541 100644
--- a/gitiles-servlet/src/test/java/com/google/gitiles/ViewFilterTest.java
+++ b/gitiles-servlet/src/test/java/com/google/gitiles/ViewFilterTest.java
@@ -20,6 +20,7 @@
 import static com.google.gitiles.GitilesFilter.ROOT_REGEX;
 
 import com.google.common.collect.ImmutableList;
+import com.google.common.net.HttpHeaders;
 import com.google.common.util.concurrent.Atomics;
 import com.google.gitiles.GitilesView.Type;
 
@@ -440,8 +441,43 @@
     assertEquals("foo/bar", view.getPathPart());
   }
 
+  public void testNormalizeParents() throws Exception {
+    RevCommit parent = repo.commit().create();
+    RevCommit master = repo.branch("refs/heads/master").commit().parent(parent).create();
+    GitilesView view;
+
+    assertEquals("/b/repo/+/master", getView("/repo/+/master").toUrl());
+    assertEquals("/b/repo/+/" + master.name(), getView("/repo/+/" + master.name()).toUrl());
+    assertEquals("/b/repo/+/" + parent.name(), getRedirectUrl("/repo/+/master~"));
+    assertEquals("/b/repo/+/" + parent.name(), getRedirectUrl("/repo/+/master^"));
+
+    view = getView("/repo/+log/master~..master/");
+    assertEquals("master", view.getRevision().getName());
+    assertEquals("master~", view.getOldRevision().getName());
+
+    view = getView("/repo/+log/master^!/");
+    assertEquals("master", view.getRevision().getName());
+    assertEquals("master^", view.getOldRevision().getName());
+  }
+
+  private String getRedirectUrl(String pathAndQuery) throws ServletException, IOException {
+    FakeHttpServletResponse res = new FakeHttpServletResponse();
+    service(pathAndQuery, Atomics.<GitilesView> newReference(), res);
+    assertEquals(302, res.getStatus());
+    return res.getHeader(HttpHeaders.LOCATION);
+  }
+
   private GitilesView getView(String pathAndQuery) throws ServletException, IOException {
-    final AtomicReference<GitilesView> view = Atomics.newReference();
+    AtomicReference<GitilesView> view = Atomics.newReference();
+    FakeHttpServletResponse res = new FakeHttpServletResponse();
+    service(pathAndQuery, view, res);
+    assertTrue("expected non-redirect status, got " + res.getStatus(),
+        res.getStatus() < 300 || res.getStatus() >= 400);
+    return view.get();
+  }
+
+  private void service(String pathAndQuery, final AtomicReference<GitilesView> view,
+      FakeHttpServletResponse res) throws ServletException, IOException {
     HttpServlet testServlet = new HttpServlet() {
       private static final long serialVersionUID = 1L;
       @Override
@@ -470,9 +506,7 @@
     } else {
       req.setPathInfo(pathAndQuery);
     }
-    dummyServlet(mf).service(req, new FakeHttpServletResponse());
-
-    return view.get();
+    dummyServlet(mf).service(req, res);
   }
 
   private MetaServlet dummyServlet(MetaFilter mf) {