diff --git a/core/dragged_connection_manager.js b/core/dragged_connection_manager.js
index 7b7947a43..09cfdab01 100644
--- a/core/dragged_connection_manager.js
+++ b/core/dragged_connection_manager.js
@@ -29,8 +29,6 @@ goog.provide('Blockly.DraggedConnectionManager');
 goog.require('Blockly.BlockAnimations');
 goog.require('Blockly.RenderedConnection');
 
-goog.require('goog.math.Coordinate');
-
 
 /**
  * Class that controls updates to connections during drags.  It is primarily
diff --git a/core/field_colour.js b/core/field_colour.js
index f3d17df1f..a6a501efa 100644
--- a/core/field_colour.js
+++ b/core/field_colour.js
@@ -29,7 +29,7 @@ goog.provide('Blockly.FieldColour');
 goog.require('Blockly.DropDownDiv');
 goog.require('Blockly.Field');
 
-goog.require('goog.style');
+goog.require('goog.math.Size');
 
 
 /**
diff --git a/core/flyout_base.js b/core/flyout_base.js
index b7897e7b1..b651f7255 100644
--- a/core/flyout_base.js
+++ b/core/flyout_base.js
@@ -37,7 +37,7 @@ goog.require('Blockly.utils');
 goog.require('Blockly.WorkspaceSvg');
 goog.require('Blockly.Xml');
 
-goog.require('goog.math.Rect');
+goog.require('goog.math.Coordinate');
 
 
 /**
diff --git a/core/insertion_marker_manager.js b/core/insertion_marker_manager.js
index e0572e4a8..8b3bd3079 100644
--- a/core/insertion_marker_manager.js
+++ b/core/insertion_marker_manager.js
@@ -30,8 +30,6 @@ goog.require('Blockly.BlockAnimations');
 goog.require('Blockly.Events.BlockMove');
 goog.require('Blockly.RenderedConnection');
 
-goog.require('goog.math.Coordinate');
-
 
 /**
  * Class that controls updates to connections during drags.  It is primarily
@@ -660,7 +658,8 @@ Blockly.InsertionMarkerManager.prototype.disconnectMarker_ = function() {
   }
 
   if (imConn.targetConnection) {
-    throw 'markerConnection_ still connected at the end of disconnectInsertionMarker';
+    throw Error('markerConnection_ still connected at the end of ' +
+        'disconnectInsertionMarker');
   }
 
   this.markerConnection_ = null;
@@ -679,8 +678,10 @@ Blockly.InsertionMarkerManager.prototype.connectMarker_ = function() {
   var imBlock = isLastInStack ? this.lastMarker_ : this.firstMarker_;
   var imConn = imBlock.getMatchingConnection(local.sourceBlock_, local);
 
-  goog.asserts.assert(imConn != this.markerConnection_,
-      'Made it to connectMarker_ even though the marker isn\'t changing');
+  if (imConn == this.markerConnection_) {
+    throw Error('Made it to connectMarker_ even though the marker isn\'t ' +
+        'changing');
+  }
 
   // Render disconnected from everything else so that we have a valid
   // connection location.
diff --git a/core/toolbox.js b/core/toolbox.js
index 890b9d2e3..3804cbc37 100644
--- a/core/toolbox.js
+++ b/core/toolbox.js
@@ -35,10 +35,10 @@ goog.require('Blockly.VerticalFlyout');
 
 goog.require('goog.events');
 goog.require('goog.events.BrowserFeature');
+goog.require('goog.events.EventType');
 goog.require('goog.html.SafeHtml');
-goog.require('goog.html.SafeStyle');
 goog.require('goog.math.Rect');
-goog.require('goog.style');
+goog.require('goog.ui.tree.BaseNode');
 goog.require('goog.ui.tree.TreeControl');
 goog.require('goog.ui.tree.TreeNode');
 
diff --git a/core/ui_menu_utils.js b/core/ui_menu_utils.js
index 695041ce7..a621827fb 100644
--- a/core/ui_menu_utils.js
+++ b/core/ui_menu_utils.js
@@ -31,6 +31,8 @@
  */
 goog.provide('Blockly.utils.uiMenu');
 
+goog.require('goog.style');
+
 
 /**
  * Get the size of a rendered goog.ui.Menu.
diff --git a/core/utils.js b/core/utils.js
index 292a76a59..e5a1f91c1 100644
--- a/core/utils.js
+++ b/core/utils.js
@@ -35,6 +35,7 @@ goog.provide('Blockly.utils');
 goog.require('Blockly.userAgent');
 
 goog.require('goog.math.Coordinate');
+goog.require('goog.style');
 
 
 /**