diff --git a/polygerrit-ui/app/elements/shared/gr-button/gr-button.js b/polygerrit-ui/app/elements/shared/gr-button/gr-button.js
index 1de704ac9c..8c9ba50996 100644
--- a/polygerrit-ui/app/elements/shared/gr-button/gr-button.js
+++ b/polygerrit-ui/app/elements/shared/gr-button/gr-button.js
@@ -91,7 +91,7 @@
 
     _disabledChanged(disabled) {
       if (disabled) {
-        this._enabledTabindex = this.getAttribute('tabindex');
+        this._enabledTabindex = this.getAttribute('tabindex') || '0';
       }
       this.setAttribute('tabindex', disabled ? '-1' : this._enabledTabindex);
       this.updateStyles();
diff --git a/polygerrit-ui/app/elements/shared/gr-button/gr-button_test.html b/polygerrit-ui/app/elements/shared/gr-button/gr-button_test.html
index d8a5443c94..bcb560a9f3 100644
--- a/polygerrit-ui/app/elements/shared/gr-button/gr-button_test.html
+++ b/polygerrit-ui/app/elements/shared/gr-button/gr-button_test.html
@@ -68,6 +68,21 @@ limitations under the License.
       assert.isTrue(element.$$('paper-button').disabled);
     });
 
+    test('tabindex should be -1 if disabled', () => {
+      element.disabled = true;
+      assert.isTrue(element.getAttribute('tabindex') === '-1');
+    });
+
+    // Regression tests for Issue: 11969
+    test('tabindex should be reset to 0 if enabled', () => {
+      element.disabled = false;
+      assert.isTrue(element.getAttribute('tabindex') === '0');
+      element.disabled = true;
+      assert.isTrue(element.getAttribute('tabindex') === '-1');
+      element.disabled = false;
+      assert.isTrue(element.getAttribute('tabindex') === '0');
+    });
+
     // 'tap' event is tested so we don't loose backward compatibility with older
     // plugins who didn't move to on-click which is faster and well supported.
     for (const eventName of ['tap', 'click']) {