diff --git a/CHANGELOG.txt b/CHANGELOG.txt
index 99b03f00b..ae4e45318 100644
--- a/CHANGELOG.txt
+++ b/CHANGELOG.txt
@@ -13,6 +13,7 @@ Changelog
  * Fix: Previewing inaccessible pages no longer fails with `ALLOWED_HOSTS = ['*']` (Robert Rollins)
  * Fix: The submit button 'spinner' no longer activates if the form has client-side validation errors (Jack Paine, Matt Westcott)
  * Fix: Overriding `MESSAGE_TAGS` in project settings no longer causes messages in the Wagtail admin to lose their styling (Tim Heap)
+ * Fix: Border added around explorer menu to stop it blending in with StreamField block listing; also fixes invisible explorer menu in Firefox 46 (Alex Gleason)
 
 
 1.4.3 (04.04.2016)
diff --git a/docs/releases/1.4.4.rst b/docs/releases/1.4.4.rst
index 70a7c3262..1be560e90 100644
--- a/docs/releases/1.4.4.rst
+++ b/docs/releases/1.4.4.rst
@@ -22,3 +22,4 @@ Bug fixes
  * Previewing inaccessible pages no longer fails with ``ALLOWED_HOSTS = ['*']`` (Robert Rollins)
  * The submit button 'spinner' no longer activates if the form has client-side validation errors (Jack Paine, Matt Westcott)
  * Overriding ``MESSAGE_TAGS`` in project settings no longer causes messages in the Wagtail admin to lose their styling (Tim Heap)
+ * Border added around explorer menu to stop it blending in with StreamField block listing; also fixes invisible explorer menu in Firefox 46 (Alex Gleason)
diff --git a/wagtail/wagtailadmin/static_src/wagtailadmin/scss/components/_main-nav.scss b/wagtail/wagtailadmin/static_src/wagtailadmin/scss/components/_main-nav.scss
index 363a95e0f..a540966f7 100644
--- a/wagtail/wagtailadmin/static_src/wagtailadmin/scss/components/_main-nav.scss
+++ b/wagtail/wagtailadmin/static_src/wagtailadmin/scss/components/_main-nav.scss
@@ -416,6 +416,17 @@ body.explorer-open {
             display: none;
         }
 
+        .explorer:after {
+            content: '';
+            width: calc(100% - 2px);
+            height: 100%;
+            position: absolute;
+            top: 0;
+            right: 0;
+            z-index: -1;
+            box-shadow: 0px 0px 2px rgba(255, 255, 255, 0.9);
+        }
+
         .nav-main {
             display: block;
         }