diff --git a/src/gtk3/widgets/_button.scss b/src/gtk3/widgets/_button.scss
--- a/src/gtk3/widgets/_button.scss
+++ b/src/gtk3/widgets/_button.scss
@@ -89,6 +89,15 @@
     background-color: gtk("@theme_button_background_backdrop");
   }
 
+  @else if $t==backdrop-hover {
+  //
+  // backdrop hover button
+  //
+    color: gtk("@theme_button_foreground_backdrop");
+    border-color: gtk("@theme_button_decoration_hover");
+    background-color: gtk("@theme_button_background_backdrop");
+  }
+
   @else if $t==backdrop-active {
   //
   // backdrop pushed button
@@ -194,6 +203,9 @@
    &:backdrop {
      @include button(backdrop);
      -gtk-icon-effect: none;
+     &:hover {
+       @include button(backdrop-hover);
+     }
      &:active, &:checked, &:focus {
        @include button(backdrop-active);
      }
diff --git a/src/gtk3/widgets/_headerbar.scss b/src/gtk3/widgets/_headerbar.scss
--- a/src/gtk3/widgets/_headerbar.scss
+++ b/src/gtk3/widgets/_headerbar.scss
@@ -45,7 +45,9 @@
     &:hover {
       @include button(hover);
       color: gtk("@theme_titlebar_foreground");
-      &:backdrop { border-color: gtk("@theme_titlebar_background_backdrop"); }
+      &:backdrop { 
+        @include button(backdrop-hover);
+      }
     }
     &:active, &:checked {
       @include button(active);
@@ -57,6 +59,9 @@
         background-color: gtk("@theme_titlebar_background_backdrop");
         border-color: gtk("@theme_titlebar_background_backdrop");
         color: gtk("@theme_titlebar_foreground_backdrop");
+        &:hover { 
+          @include button(backdrop-hover);
+        }
       }
     }