diff --git a/components/navbar.vue b/components/navbar.vue
index 29254ce..d60d0f5 100644
--- a/components/navbar.vue
+++ b/components/navbar.vue
@@ -153,7 +153,10 @@
 <script>
 export default {
   props: {
-    showBackButton: Boolean,
+    showBackButton: {
+      type: Boolean,
+      default: false,
+    },
   },
   data() {
     return {
diff --git a/pages/diff.vue b/pages/diff.vue
index c0bc871..703e8fe 100644
--- a/pages/diff.vue
+++ b/pages/diff.vue
@@ -1,6 +1,6 @@
 <template>
   <div class="contents">
-    <Navbar show-back-button="true">
+    <Navbar :show-back-button="true">
       <template #right>
         <button
           type="button"