diff --git a/index.html b/index.html
index 5aac353..8002f21 100644
--- a/index.html
+++ b/index.html
@@ -32,8 +32,10 @@
               </template>
             </td>
             <td>
-              <span class="glyphicon glyphicon-list"></span>{{ book.series ? book.series.name : '' }}
-              <span class="badge">{{ book.series ? book.series.idx : '' }}</span>
+              <template v-if="book.series">
+                <span class="glyphicon glyphicon-list"></span>{{ book.series ? book.series.name : '' }}
+                <span class="badge">{{ book.series ? book.series.idx : '' }}</span>
+              </template>
             </td>
           </tr>
         </table>