diff --git a/resources/celerity/map.php b/resources/celerity/map.php
--- a/resources/celerity/map.php
+++ b/resources/celerity/map.php
@@ -7,7 +7,7 @@
  */
 return array(
   'names' => array(
-    'core.pkg.css' => '852bf913',
+    'core.pkg.css' => '288cae1c',
     'core.pkg.js' => 'a590b451',
     'darkconsole.pkg.js' => 'e7393ebb',
     'differential.pkg.css' => '9451634c',
@@ -110,7 +110,7 @@
     'rsrc/css/core/core.css' => 'a76cefc9',
     'rsrc/css/core/remarkup.css' => 'c3c837ee',
     'rsrc/css/core/syntax.css' => '9fd11da8',
-    'rsrc/css/core/z-index.css' => '63689f49',
+    'rsrc/css/core/z-index.css' => '57ddcaa2',
     'rsrc/css/diviner/diviner-shared.css' => '5a337049',
     'rsrc/css/font/font-awesome.css' => 'e2e712fe',
     'rsrc/css/font/font-lato.css' => '5ab1a46a',
@@ -152,7 +152,7 @@
     'rsrc/css/phui/phui-tag-view.css' => '402691cc',
     'rsrc/css/phui/phui-text.css' => 'cf019f54',
     'rsrc/css/phui/phui-timeline-view.css' => 'fc23e7b7',
-    'rsrc/css/phui/phui-workboard-view.css' => '935b19d6',
+    'rsrc/css/phui/phui-workboard-view.css' => '6a20991a',
     'rsrc/css/phui/phui-workpanel-view.css' => '00558537',
     'rsrc/css/sprite-login.css' => '245e6e9e',
     'rsrc/css/sprite-main-header.css' => 'f07bbb87',
@@ -764,7 +764,7 @@
     'phabricator-uiexample-reactor-select' => 'a155550f',
     'phabricator-uiexample-reactor-sendclass' => '1def2711',
     'phabricator-uiexample-reactor-sendproperties' => 'b1f0ccee',
-    'phabricator-zindex-css' => '63689f49',
+    'phabricator-zindex-css' => '57ddcaa2',
     'phame-css' => '3259b53d',
     'pholio-css' => '95174bdd',
     'pholio-edit-css' => '3ad9d1ee',
@@ -808,7 +808,7 @@
     'phui-text-css' => 'cf019f54',
     'phui-theme-css' => '6b451f24',
     'phui-timeline-view-css' => 'fc23e7b7',
-    'phui-workboard-view-css' => '935b19d6',
+    'phui-workboard-view-css' => '6a20991a',
     'phui-workpanel-view-css' => '00558537',
     'phuix-action-list-view' => 'b5c256b8',
     'phuix-action-view' => '8cf6d262',
diff --git a/webroot/rsrc/css/core/z-index.css b/webroot/rsrc/css/core/z-index.css
--- a/webroot/rsrc/css/core/z-index.css
+++ b/webroot/rsrc/css/core/z-index.css
@@ -52,6 +52,10 @@
   z-index: 4;
 }
 
+.project-board-header {
+  z-index: 4;
+}
+
 .conpherence-layout .conpherence-no-threads {
   z-index: 4;
 }
diff --git a/webroot/rsrc/css/phui/phui-workboard-view.css b/webroot/rsrc/css/phui/phui-workboard-view.css
--- a/webroot/rsrc/css/phui/phui-workboard-view.css
+++ b/webroot/rsrc/css/phui/phui-workboard-view.css
@@ -103,6 +103,7 @@
   background-color: #fff;
   border-bottom: 1px solid {$lightblueborder};
   padding: 12px;
+  position: relative;
 }
 
 .device .project-board-header {