diff --git a/conf/default.conf.php b/conf/default.conf.php
index 229c9e4335..581b062938 100644
--- a/conf/default.conf.php
+++ b/conf/default.conf.php
@@ -349,4 +349,13 @@ return array(
   // unlikely that you need to modify this.
   'celerity.resource-hash' => 'd9455ea150622ee044f7931dabfa52aa',
 
+  // In a development environment, it is desirable to force static resources
+  // (CSS and JS) to be read from disk on every request, so that edits to them
+  // appear when you reload the page even if you haven't updated the resource
+  // maps. This setting ensures requests will be verified against the state on
+  // disk. Generally, you should leave this off in production (caching behavior
+  // and performance improve with it off) but turn it on in development. (These
+  // settings are the defaults.)
+  'celerity.force-disk-reads' => false,
+
 );
diff --git a/conf/development.conf.php b/conf/development.conf.php
index 51a1c1a6f0..3e2e8d0b55 100644
--- a/conf/development.conf.php
+++ b/conf/development.conf.php
@@ -19,5 +19,6 @@
 return array(
 
   'darkconsole.enabled' => true,
+  'celerity.force-disk-reads' => true,
 
 ) + phabricator_read_config_file('default');
diff --git a/src/__celerity_resource_map__.php b/src/__celerity_resource_map__.php
index c511556d8e..a81a9261b0 100644
--- a/src/__celerity_resource_map__.php
+++ b/src/__celerity_resource_map__.php
@@ -390,7 +390,7 @@ celerity_register_resource_map(array(
   ),
   'javelin-behavior-differential-show-more' =>
   array(
-    'uri' => '/res/7a844635/rsrc/js/application/differential/behavior-show-more.js',
+    'uri' => '/res/9cbf1c9c/rsrc/js/application/differential/behavior-show-more.js',
     'type' => 'js',
     'requires' =>
     array(
@@ -867,7 +867,7 @@ celerity_register_resource_map(array(
   ),
   'phabricator-shaped-request' =>
   array(
-    'uri' => '/res/1f0ef02b/rsrc/js/application/core/ShapedRequest.js',
+    'uri' => '/res/7b1522d3/rsrc/js/application/core/ShapedRequest.js',
     'type' => 'js',
     'requires' =>
     array(
@@ -1005,7 +1005,7 @@ celerity_register_resource_map(array(
       'uri' => '/res/pkg/ac70e6b7/core.pkg.css',
       'type' => 'css',
     ),
-    'b17926e1' =>
+    'c5d10dfe' =>
     array (
       'name' => 'differential.pkg.js',
       'symbols' =>
@@ -1016,7 +1016,7 @@ celerity_register_resource_map(array(
         3 => 'javelin-behavior-differential-show-more',
         4 => 'javelin-behavior-differential-diff-radios',
       ),
-      'uri' => '/res/pkg/b17926e1/differential.pkg.js',
+      'uri' => '/res/pkg/c5d10dfe/differential.pkg.js',
       'type' => 'js',
     ),
   ),
@@ -1042,11 +1042,11 @@ celerity_register_resource_map(array(
     'diffusion-commit-view-css' => '03ef179e',
     'javelin-behavior' => '7d23deb1',
     'javelin-behavior-aphront-basic-tokenizer' => '33f413ef',
-    'javelin-behavior-differential-diff-radios' => 'b17926e1',
-    'javelin-behavior-differential-edit-inline-comments' => 'b17926e1',
-    'javelin-behavior-differential-feedback-preview' => 'b17926e1',
-    'javelin-behavior-differential-populate' => 'b17926e1',
-    'javelin-behavior-differential-show-more' => 'b17926e1',
+    'javelin-behavior-differential-diff-radios' => 'c5d10dfe',
+    'javelin-behavior-differential-edit-inline-comments' => 'c5d10dfe',
+    'javelin-behavior-differential-feedback-preview' => 'c5d10dfe',
+    'javelin-behavior-differential-populate' => 'c5d10dfe',
+    'javelin-behavior-differential-show-more' => 'c5d10dfe',
     'javelin-behavior-workflow' => '122a6b6d',
     'javelin-dom' => '7d23deb1',
     'javelin-event' => '7d23deb1',
diff --git a/src/infrastructure/celerity/controller/CelerityResourceController.php b/src/infrastructure/celerity/controller/CelerityResourceController.php
index fb5a1ca35e..2b09c7899e 100644
--- a/src/infrastructure/celerity/controller/CelerityResourceController.php
+++ b/src/infrastructure/celerity/controller/CelerityResourceController.php
@@ -38,7 +38,8 @@ class CelerityResourceController extends AphrontController {
       throw new Exception("Only CSS and JS resources may be served.");
     }
 
-    if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE'])) {
+    if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) &&
+        !PhabricatorEnv::getEnvConfig('celerity.force-disk-reads')) {
       // Return a "304 Not Modified". We don't care about the value of this
       // field since we never change what resource is served by a given URI.
       return $this->makeResponseCacheable(new Aphront304Response());
diff --git a/webroot/rsrc/js/application/core/ShapedRequest.js b/webroot/rsrc/js/application/core/ShapedRequest.js
index 5decf2b387..d993e6680a 100644
--- a/webroot/rsrc/js/application/core/ShapedRequest.js
+++ b/webroot/rsrc/js/application/core/ShapedRequest.js
@@ -51,9 +51,11 @@ JX.install('PhabricatorShapedRequest', {
         var request = new JX.Request(this._uri, JX.bind(this, function(r) {
           this._callback(r);
 
-          this._min = new Date().getTime() + this._rateLimit;
+          this._min = new Date().getTime() + this.getRateLimit();
           this._defer && this._defer.stop();
-          this._defer = JX.defer(JX.bind(this, this.trigger), this._rateLimit);
+          this._defer = JX.defer(
+            JX.bind(this, this.trigger),
+            this.getRateLimit());
         }));
         request.listen('finally', JX.bind(this, function() {
           this._request = null;
@@ -62,7 +64,9 @@ JX.install('PhabricatorShapedRequest', {
         request.setTimeout(this.getFrequency());
         request.send();
       } else {
-        this._defer = JX.defer(JX.bind(this, this.trigger), this._frequency);
+        this._defer = JX.defer(
+          JX.bind(this, this.trigger),
+          this.getFrequency());
       }
     },
 
@@ -82,7 +86,7 @@ JX.install('PhabricatorShapedRequest', {
   },
 
   properties : {
-    rateLimit : 250,
-    frequency : 750
+    rateLimit : 500,
+    frequency : 1000
   }
 });