diff --git a/blockly_compressed.js b/blockly_compressed.js
index 108144e9a..522e04dae 100644
--- a/blockly_compressed.js
+++ b/blockly_compressed.js
@@ -912,9 +912,8 @@ Blockly.Connection.prototype.targetBlock=function(){return this.targetConnection
 Blockly.Connection.prototype.bumpAwayFrom_=function(a){if(0==Blockly.dragMode_){var b=this.sourceBlock_.getRootBlock();if(!b.isInFlyout){var c=!1;if(!b.isMovable()){b=a.getSourceBlock().getRootBlock();if(!b.isMovable())return;a=this;c=!0}b.getSvgRoot().parentNode.appendChild(b.getSvgRoot());var d=a.x_+Blockly.SNAP_RADIUS-this.x_;a=a.y_+Blockly.SNAP_RADIUS-this.y_;c&&(a=-a);b.RTL&&(d=-d);b.moveBy(d,a)}}};
 Blockly.Connection.prototype.moveTo=function(a,b){this.inDB_&&this.db_.removeConnection_(this);this.x_=a;this.y_=b;this.hidden_||this.db_.addConnection(this)};Blockly.Connection.prototype.moveBy=function(a,b){this.moveTo(this.x_+a,this.y_+b)};
 Blockly.Connection.prototype.tighten_=function(){var a=this.targetConnection.x_-this.x_,b=this.targetConnection.y_-this.y_;if(0!=a||0!=b){var c=this.targetBlock(),d=c.getSvgRoot();if(!d)throw"block is not rendered.";d=Blockly.getRelativeXY_(d);c.getSvgRoot().setAttribute("transform","translate("+(d.x-a)+","+(d.y-b)+")");c.moveConnections_(-a,-b)}};Blockly.Connection.prototype.closest=function(a,b,c){return this.dbOpposite_.searchForClosest(this,a,b,c)};
-Blockly.Connection.prototype.checkType_=function(a){var b=this.targetBlock();if(b&&!b.isMovable()&&!this.sourceBlock_.isMovable()||(b=a.targetBlock())&&!b.isMovable()&&!a.getSourceBlock().isMovable())return!1;if(!this.check_||!a.check_)return!0;for(b=0;b<this.check_.length;b++)if(-1!=a.check_.indexOf(this.check_[b]))return!0;return!1};
-Blockly.Connection.prototype.setCheck=function(a){a?(goog.isArray(a)||(a=[a]),this.check_=a,this.targetConnection&&!this.checkType_(this.targetConnection)&&((this.isSuperior()?this.targetBlock():this.sourceBlock_).unplug(),this.sourceBlock_.bumpNeighbours_())):this.check_=null;return this};Blockly.Connection.prototype.setShadowDom=function(a){this.shadowDom_=a};Blockly.Connection.prototype.getShadowDom=function(){return this.shadowDom_};
-Blockly.Connection.prototype.neighbours_=function(a){return this.dbOpposite_.getNeighbours(this,a)};Blockly.Connection.prototype.setHidden=function(a){(this.hidden_=a)&&this.inDB_?this.db_.removeConnection_(this):a||this.inDB_||this.db_.addConnection(this)};
+Blockly.Connection.prototype.checkType_=function(a){if(!this.check_||!a.check_)return!0;for(var b=0;b<this.check_.length;b++)if(-1!=a.check_.indexOf(this.check_[b]))return!0;return!1};Blockly.Connection.prototype.setCheck=function(a){a?(goog.isArray(a)||(a=[a]),this.check_=a,this.targetConnection&&!this.checkType_(this.targetConnection)&&((this.isSuperior()?this.targetBlock():this.sourceBlock_).unplug(),this.sourceBlock_.bumpNeighbours_())):this.check_=null;return this};
+Blockly.Connection.prototype.setShadowDom=function(a){this.shadowDom_=a};Blockly.Connection.prototype.getShadowDom=function(){return this.shadowDom_};Blockly.Connection.prototype.neighbours_=function(a){return this.dbOpposite_.getNeighbours(this,a)};Blockly.Connection.prototype.setHidden=function(a){(this.hidden_=a)&&this.inDB_?this.db_.removeConnection_(this):a||this.inDB_||this.db_.addConnection(this)};
 Blockly.Connection.prototype.hideAll=function(){this.setHidden(!0);if(this.targetConnection)for(var a=this.targetBlock().getDescendants(),b=0;b<a.length;b++){for(var c=a[b],d=c.getConnections_(!0),e=0;e<d.length;e++)d[e].setHidden(!0);c=c.getIcons();for(d=0;d<c.length;d++)c[d].setVisible(!1)}};
 Blockly.Connection.prototype.unhideAll=function(){this.setHidden(!1);var a=[];if(this.type!=Blockly.INPUT_VALUE&&this.type!=Blockly.NEXT_STATEMENT)return a;var b=this.targetBlock();if(b){var c;b.isCollapsed()?(c=[],b.outputConnection&&c.push(b.outputConnection),b.nextConnection&&c.push(b.nextConnection),b.previousConnection&&c.push(b.previousConnection)):c=b.getConnections_(!0);for(var d=0;d<c.length;d++)a.push.apply(a,c[d].unhideAll());a.length||(a[0]=b)}return a};
 Blockly.Connection.prototype.highlight=function(){var a;a=this.type==Blockly.INPUT_VALUE||this.type==Blockly.OUTPUT_VALUE?"m 0,0 "+Blockly.BlockSvg.TAB_PATH_DOWN+" v 5":"m -20,0 h 5 "+Blockly.BlockSvg.NOTCH_PATH_LEFT+" h 5";var b=this.sourceBlock_.getRelativeToSurfaceXY();Blockly.Connection.highlightedPath_=Blockly.createSvgElement("path",{"class":"blocklyHighlightedConnectionPath",d:a,transform:"translate("+(this.x_-b.x)+","+(this.y_-b.y)+")"+(this.sourceBlock_.RTL?" scale(-1 1)":"")},this.sourceBlock_.getSvgRoot())};
@@ -1091,9 +1090,9 @@ e.alt);break;case "field_date":if(Blockly.FieldDate){f=new Blockly.FieldDate(e.d
 Blockly.Block.prototype.appendInput_=function(a,b){var c=null;if(a==Blockly.INPUT_VALUE||a==Blockly.NEXT_STATEMENT)c=new Blockly.Connection(this,a);c=new Blockly.Input(a,b,this,c);this.inputList.push(c);this.rendered&&(this.render(),this.bumpNeighbours_());return c};
 Blockly.Block.prototype.moveInputBefore=function(a,b){if(a!=b){for(var c=-1,d=b?-1:this.inputList.length,e=0,f;f=this.inputList[e];e++)if(f.name==a){if(c=e,-1!=d)break}else if(b&&f.name==b&&(d=e,-1!=c))break;goog.asserts.assert(-1!=c,'Named input "%s" not found.',a);goog.asserts.assert(-1!=d,'Reference input "%s" not found.',b);this.moveNumberedInputBefore(c,d)}};
 Blockly.Block.prototype.moveNumberedInputBefore=function(a,b){goog.asserts.assert(a!=b,"Can't move input to itself.");goog.asserts.assert(a<this.inputList.length,"Input index "+a+" out of bounds.");goog.asserts.assert(b<=this.inputList.length,"Reference input "+b+" out of bounds.");var c=this.inputList[a];this.inputList.splice(a,1);a<b&&b--;this.inputList.splice(b,0,c);this.rendered&&(this.render(),this.bumpNeighbours_())};
-Blockly.Block.prototype.removeInput=function(a,b){for(var c=0,d;d=this.inputList[c];c++)if(d.name==a){d.connection&&d.connection.targetConnection&&d.connection.targetBlock().unplug();d.dispose();this.inputList.splice(c,1);this.rendered&&(this.render(),this.bumpNeighbours_());return}b||goog.asserts.fail('Input "%s" not found.',a)};Blockly.Block.prototype.getInput=function(a){for(var b=0,c;c=this.inputList[b];b++)if(c.name==a)return c;return null};
-Blockly.Block.prototype.getInputTargetBlock=function(a){return(a=this.getInput(a))&&a.connection&&a.connection.targetBlock()};Blockly.Block.prototype.getCommentText=function(){return this.comment||""};Blockly.Block.prototype.setCommentText=function(a){this.comment!=a&&(Blockly.Events.fire(new Blockly.Events.Change(this,"comment",null,this.comment,a||"")),this.comment=a)};Blockly.Block.prototype.setWarningText=function(a){};Blockly.Block.prototype.setMutator=function(a){};
-Blockly.Block.prototype.getRelativeToSurfaceXY=function(){return this.xy_};Blockly.Block.prototype.moveBy=function(a,b){goog.asserts.assert(!this.parentBlock_,"Block has parent.");var c=new Blockly.Events.Move(this);this.xy_.translate(a,b);c.recordNew();Blockly.Events.fire(c)};Blockly.Block.BlockDB_=Object.create(null);Blockly.Block.getById=function(a){return Blockly.Block.BlockDB_[a]||null};Blockly.ContextMenu={};Blockly.ContextMenu.currentBlock=null;
+Blockly.Block.prototype.removeInput=function(a,b){for(var c=0,d;d=this.inputList[c];c++)if(d.name==a){if(d.connection&&d.connection.targetConnection){d.connection.setShadowDom(null);var e=d.connection.targetBlock();e.isShadow()?e.dispose():e.unplug()}d.dispose();this.inputList.splice(c,1);this.rendered&&(this.render(),this.bumpNeighbours_());return}b||goog.asserts.fail('Input "%s" not found.',a)};
+Blockly.Block.prototype.getInput=function(a){for(var b=0,c;c=this.inputList[b];b++)if(c.name==a)return c;return null};Blockly.Block.prototype.getInputTargetBlock=function(a){return(a=this.getInput(a))&&a.connection&&a.connection.targetBlock()};Blockly.Block.prototype.getCommentText=function(){return this.comment||""};Blockly.Block.prototype.setCommentText=function(a){this.comment!=a&&(Blockly.Events.fire(new Blockly.Events.Change(this,"comment",null,this.comment,a||"")),this.comment=a)};
+Blockly.Block.prototype.setWarningText=function(a){};Blockly.Block.prototype.setMutator=function(a){};Blockly.Block.prototype.getRelativeToSurfaceXY=function(){return this.xy_};Blockly.Block.prototype.moveBy=function(a,b){goog.asserts.assert(!this.parentBlock_,"Block has parent.");var c=new Blockly.Events.Move(this);this.xy_.translate(a,b);c.recordNew();Blockly.Events.fire(c)};Blockly.Block.BlockDB_=Object.create(null);Blockly.Block.getById=function(a){return Blockly.Block.BlockDB_[a]||null};Blockly.ContextMenu={};Blockly.ContextMenu.currentBlock=null;
 Blockly.ContextMenu.show=function(a,b,c){Blockly.WidgetDiv.show(Blockly.ContextMenu,c,null);if(b.length){var d=new goog.ui.Menu;d.setRightToLeft(c);for(var e=0,f;f=b[e];e++){var g=new goog.ui.MenuItem(f.text);g.setRightToLeft(c);d.addChild(g,!0);g.setEnabled(f.enabled);f.enabled&&goog.events.listen(g,goog.ui.Component.EventType.ACTION,f.callback)}goog.events.listen(d,goog.ui.Component.EventType.ACTION,Blockly.ContextMenu.hide);b=goog.dom.getViewportSize();f=goog.style.getViewportPageOffset(document);
 d.render(Blockly.WidgetDiv.DIV);var h=d.getElement();Blockly.addClass_(h,"blocklyContextMenu");var g=goog.style.getSize(h),e=a.clientX+f.x,k=a.clientY+f.y;a.clientY+g.height>=b.height&&(k-=g.height);c?g.width>=a.clientX&&(e+=g.width):a.clientX+g.width>=b.width&&(e-=g.width);Blockly.WidgetDiv.position(e,k,b,f,c);d.setAllowAutoFocus(!0);setTimeout(function(){h.focus()},1);Blockly.ContextMenu.currentBlock=null}else Blockly.ContextMenu.hide()};
 Blockly.ContextMenu.hide=function(){Blockly.WidgetDiv.hideIfOwner(Blockly.ContextMenu);Blockly.ContextMenu.currentBlock=null};
diff --git a/core/connection.js b/core/connection.js
index 14c07b36f..0d98dbf45 100644
--- a/core/connection.js
+++ b/core/connection.js
@@ -375,9 +375,8 @@ Blockly.Connection.prototype.isConnectionAllowed = function(candidate,
 
   // Offering to connect the left (male) of a value block to an already
   // connected value pair is ok, we'll splice it in.
-  // However, don't offer to splice into an unmovable block.
-  if (candidate.type == Blockly.INPUT_VALUE &&
-      candidate.targetConnection &&
+  // However, don't offer to splice into an immovable block.
+  if (candidate.type == Blockly.INPUT_VALUE && candidate.targetConnection &&
       !candidate.targetBlock().isMovable() &&
       !candidate.targetBlock().isShadow()) {
     return false;
@@ -674,17 +673,6 @@ Blockly.Connection.prototype.closest = function(maxLimit, dx, dy) {
  * @private
  */
 Blockly.Connection.prototype.checkType_ = function(otherConnection) {
-  // Don't split a connection where both sides are immovable.
-  var thisTargetBlock = this.targetBlock();
-  if (thisTargetBlock && !thisTargetBlock.isMovable() &&
-      !this.sourceBlock_.isMovable()) {
-    return false;
-  }
-  var otherTargetBlock = otherConnection.targetBlock();
-  if (otherTargetBlock && !otherTargetBlock.isMovable() &&
-      !otherConnection.getSourceBlock().isMovable()) {
-    return false;
-  }
   if (!this.check_ || !otherConnection.check_) {
     // One or both sides are promiscuous enough that anything will fit.
     return true;
diff --git a/demos/blockfactory/blocks.js b/demos/blockfactory/blocks.js
index 6c59c1d92..5a9752625 100644
--- a/demos/blockfactory/blocks.js
+++ b/demos/blockfactory/blocks.js
@@ -73,34 +73,36 @@ Blockly.Blocks['factory_base'] = {
     var bottomExists = this.getInput('BOTTOMTYPE');
     if (option == 'LEFT') {
       if (!outputExists) {
-        this.appendValueInput('OUTPUTTYPE')
-            .setCheck('Type')
-            .appendField('output type');
-        this.moveInputBefore('OUTPUTTYPE', 'COLOUR');
+        this.addTypeInput_('OUTPUTTYPE', 'output type');
       }
     } else if (outputExists) {
       this.removeInput('OUTPUTTYPE');
     }
     if (option == 'TOP' || option == 'BOTH') {
       if (!topExists) {
-        this.appendValueInput('TOPTYPE')
-            .setCheck('Type')
-            .appendField('top type');
-        this.moveInputBefore('TOPTYPE', 'COLOUR');
+        this.addTypeInput_('TOPTYPE', 'top type');
       }
     } else if (topExists) {
       this.removeInput('TOPTYPE');
     }
     if (option == 'BOTTOM' || option == 'BOTH') {
       if (!bottomExists) {
-        this.appendValueInput('BOTTOMTYPE')
-            .setCheck('Type')
-            .appendField('bottom type');
-        this.moveInputBefore('BOTTOMTYPE', 'COLOUR');
+        this.addTypeInput_('BOTTOMTYPE', 'bottom type');
       }
     } else if (bottomExists) {
       this.removeInput('BOTTOMTYPE');
     }
+  },
+  addTypeInput_: function(name, label) {
+    this.appendValueInput(name)
+        .setCheck('Type')
+        .appendField(label);
+    this.moveInputBefore(name, 'COLOUR');
+    var type = this.workspace.newBlock('type_null');
+    type.setShadow(true);
+    type.outputConnection.connect(this.getInput(name).connection);
+    type.initSvg();
+    type.render();
   }
 };