diff --git a/polygerrit-ui/app/elements/core/gr-router/gr-router.js b/polygerrit-ui/app/elements/core/gr-router/gr-router.js
index f550af4acf..38997225e0 100644
--- a/polygerrit-ui/app/elements/core/gr-router/gr-router.js
+++ b/polygerrit-ui/app/elements/core/gr-router/gr-router.js
@@ -91,6 +91,15 @@
     SETTINGS_LEGACY: /^\/settings\/VE\/(\S+)/,
   };
 
+  /**
+   * Pattern to recognize and parse the diff line locations as they appear in
+   * the hash of diff URLs. In this format, a number on its own indicates that
+   * line number in the revision of the diff. A number prefixed by either an 'a'
+   * or a 'b' indicates that line number of the base of the diff.
+   * @type {RegExp}
+   */
+  const LINE_ADDRESS_PATTERN = /^([ab]?)(\d+)$/;
+
   // Polymer makes `app` intrinsically defined on the window by virtue of the
   // custom element having the id "app", but it is made explicit here.
   const app = document.querySelector('#app');
@@ -300,6 +309,15 @@
       return canonicalPath.split('#').slice(1).join('#');
     },
 
+    _parseLineAddress(hash) {
+      const match = hash.match(LINE_ADDRESS_PATTERN);
+      if (!match) { return null; }
+      return {
+        leftSide: !!match[1],
+        lineNum: parseInt(match[2], 10),
+      };
+    },
+
     /**
      * Check to see if the user is logged in and return a promise that only
      * resolves if the user is logged in. If the user us not logged in, the
@@ -745,6 +763,8 @@
     },
 
     _handleChangeOrDiffRoute(ctx) {
+      const isDiffView = ctx.params[8];
+
       // Parameter order is based on the regex group number matched.
       const params = {
         project: ctx.params[0],
@@ -752,17 +772,23 @@
         basePatchNum: ctx.params[4],
         patchNum: ctx.params[6],
         path: ctx.params[8],
-        view: ctx.params[8] ?
-            Gerrit.Nav.View.DIFF : Gerrit.Nav.View.CHANGE,
-        hash: ctx.hash,
+        view: isDiffView ? Gerrit.Nav.View.DIFF : Gerrit.Nav.View.CHANGE,
       };
+
+      if (isDiffView) {
+        const address = this._parseLineAddress(ctx.hash);
+        if (address) {
+          params.leftSide = address.leftSide;
+          params.lineNum = address.lineNum;
+        }
+      }
+
       const needsRedirect = this._normalizePatchRangeParams(params);
       if (needsRedirect) {
         this._redirect(this._generateUrl(params));
       } else {
         this._setParams(params);
-        this._restAPI.setInProjectLookup(params.changeNum,
-            params.project);
+        this._restAPI.setInProjectLookup(params.changeNum, params.project);
       }
     },
 
@@ -793,10 +819,15 @@
         basePatchNum: ctx.params[2],
         patchNum: ctx.params[4],
         path: ctx.params[5],
-        hash: ctx.hash,
         view: Gerrit.Nav.View.DIFF,
       };
 
+      const address = this._parseLineAddress(ctx.hash);
+      if (address) {
+        params.leftSide = address.leftSide;
+        params.lineNum = address.lineNum;
+      }
+
       this._normalizeLegacyRouteParams(params);
     },
 
diff --git a/polygerrit-ui/app/elements/core/gr-router/gr-router_test.html b/polygerrit-ui/app/elements/core/gr-router/gr-router_test.html
index fe0c812f5d..3864a7d682 100644
--- a/polygerrit-ui/app/elements/core/gr-router/gr-router_test.html
+++ b/polygerrit-ui/app/elements/core/gr-router/gr-router_test.html
@@ -65,6 +65,39 @@ limitations under the License.
       assert.equal(hash, 'foo#bar#baz');
     });
 
+    suite('_parseLineAddress', () => {
+      test('returns null for empty and invalid hashes', () => {
+        let actual = element._parseLineAddress('');
+        assert.isNull(actual);
+
+        actual = element._parseLineAddress('foobar');
+        assert.isNull(actual);
+
+        actual = element._parseLineAddress('foo123');
+        assert.isNull(actual);
+
+        actual = element._parseLineAddress('123bar');
+        assert.isNull(actual);
+      });
+
+      test('parses correctly', () => {
+        let actual = element._parseLineAddress('1234');
+        assert.isOk(actual);
+        assert.equal(actual.lineNum, 1234);
+        assert.isFalse(actual.leftSide);
+
+        actual = element._parseLineAddress('a4');
+        assert.isOk(actual);
+        assert.equal(actual.lineNum, 4);
+        assert.isTrue(actual.leftSide);
+
+        actual = element._parseLineAddress('b77');
+        assert.isOk(actual);
+        assert.equal(actual.lineNum, 77);
+        assert.isTrue(actual.leftSide);
+      });
+    });
+
     test('_startRouter requires auth for the right handlers', () => {
       // This test encodes the lists of route handler methods that gr-router
       // automatically checks for authentication before triggering.
@@ -903,8 +936,9 @@ limitations under the License.
             basePatchNum: 3,
             patchNum: 8,
             view: Gerrit.Nav.View.DIFF,
-            hash: 'b123',
             path: 'foo/bar',
+            lineNum: 123,
+            leftSide: true,
           });
         });
 
@@ -967,7 +1001,6 @@ limitations under the License.
               basePatchNum: 4,
               patchNum: 7,
               path: null,
-              hash: '',
             });
             assert.isFalse(redirectStub.called);
             assert.isTrue(normalizeRangeStub.called);
@@ -984,7 +1017,8 @@ limitations under the License.
               basePatchNum: 4,
               patchNum: 7,
               path: 'foo/bar/baz',
-              hash: 'b44',
+              leftSide: true,
+              lineNum: 44,
             });
             assert.isFalse(redirectStub.called);
             assert.isTrue(normalizeRangeStub.called);
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view.js b/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view.js
index 409fd09bb3..56be27def4 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view.js
+++ b/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view.js
@@ -26,8 +26,6 @@
     RIGHT: 'right',
   };
 
-  const HASH_PATTERN = /^[ab]?\d+$/;
-
   Polymer({
     is: 'gr-diff-view',
 
@@ -467,7 +465,7 @@
     _paramsChanged(value) {
       if (value.view !== Gerrit.Nav.View.DIFF) { return; }
 
-      this._loadHash(this.params.hash);
+      this._initCursor(this.params);
 
       this._changeNum = value.changeNum;
       this._patchRange = {
@@ -539,18 +537,16 @@
     },
 
     /**
-     * If the URL hash is a diff address then configure the diff cursor.
+     * If the params specify a diff address then configure the diff cursor.
      */
-    _loadHash(hash) {
-      hash = (hash || '').replace(/^#/, '');
-      if (!HASH_PATTERN.test(hash)) { return; }
-      if (hash[0] === 'a' || hash[0] === 'b') {
+    _initCursor(params) {
+      if (params.lineNum === undefined) { return; }
+      if (params.leftSide) {
         this.$.cursor.side = DiffSides.LEFT;
-        hash = hash.substring(1);
       } else {
         this.$.cursor.side = DiffSides.RIGHT;
       }
-      this.$.cursor.initialLineNumber = parseInt(hash, 10);
+      this.$.cursor.initialLineNumber = params.lineNum;
     },
 
     _pathChanged(path) {
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view_test.html b/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view_test.html
index 250e0f509b..e239bf0457 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view_test.html
+++ b/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view_test.html
@@ -509,7 +509,7 @@ limitations under the License.
         getDiffComments() { return Promise.resolve({}); },
       });
       sandbox.stub(element.$.diff, 'reload');
-      sandbox.stub(element, '_loadHash');
+      sandbox.stub(element, '_initCursor');
 
       element._loggedIn = true;
       element.params = {
@@ -522,7 +522,7 @@ limitations under the License.
       };
 
       flush(() => {
-        assert.isTrue(element._loadHash.lastCall.calledWithExactly(10));
+        assert.isTrue(element._initCursor.calledOnce);
         done();
       });
     });
@@ -573,31 +573,31 @@ limitations under the License.
       assert.equal(select.nativeSelect.value, 'SIDE_BY_SIDE');
     });
 
-    test('_loadHash', () => {
+    test('_initCursor', () => {
       assert.isNotOk(element.$.cursor.initialLineNumber);
 
-      // Ignores invalid hashes:
-      element._loadHash('not valid');
+      // Does nothing when params specify no cursor address:
+      element._initCursor({});
       assert.isNotOk(element.$.cursor.initialLineNumber);
 
-      // Ignores null hash:
-      element._loadHash(null);
+      // Does nothing when params specify side but no number:
+      element._initCursor({leftSide: true});
       assert.isNotOk(element.$.cursor.initialLineNumber);
 
-      // Revision hash:
-      element._loadHash('234');
+      // Revision hash: specifies lineNum but not side.
+      element._initCursor({lineNum: 234});
       assert.equal(element.$.cursor.initialLineNumber, 234);
       assert.equal(element.$.cursor.side, 'right');
 
-      // Base hash:
-      element._loadHash('b345');
+      // Base hash: specifies lineNum and side.
+      element._initCursor({leftSide: true, lineNum: 345});
       assert.equal(element.$.cursor.initialLineNumber, 345);
       assert.equal(element.$.cursor.side, 'left');
 
-      // GWT-style base hash:
-      element._loadHash('a123');
+      // Specifies right side:
+      element._initCursor({leftSide: false, lineNum: 123});
       assert.equal(element.$.cursor.initialLineNumber, 123);
-      assert.equal(element.$.cursor.side, 'left');
+      assert.equal(element.$.cursor.side, 'right');
     });
 
     test('_shortenPath with long path should add ellipsis', () => {