diff --git a/blocks/lists.js b/blocks/lists.js
index 44167685e..37c53ee98 100644
--- a/blocks/lists.js
+++ b/blocks/lists.js
@@ -176,7 +176,7 @@ Blockly.Blocks['lists_create_with'] = {
     var itemBlock = containerBlock.getInputTargetBlock('STACK');
     // Count number of inputs.
     var connections = [];
-    while (itemBlock) {
+    while (itemBlock && !itemBlock.isInsertionMarker()) {
       connections.push(itemBlock.valueConnection_);
       itemBlock = itemBlock.nextConnection &&
           itemBlock.nextConnection.targetBlock();
diff --git a/blocks/logic.js b/blocks/logic.js
index afec94d3f..c45089dec 100644
--- a/blocks/logic.js
+++ b/blocks/logic.js
@@ -365,7 +365,7 @@ Blockly.Constants.Logic.CONTROLS_IF_MUTATOR_MIXIN = {
     var valueConnections = [null];
     var statementConnections = [null];
     var elseStatementConnection = null;
-    while (clauseBlock) {
+    while (clauseBlock && !clauseBlock.isInsertionMarker()) {
       switch (clauseBlock.type) {
         case 'controls_if_elseif':
           this.elseifCount_++;
diff --git a/blocks/procedures.js b/blocks/procedures.js
index ad5d78042..242fa4f0b 100644
--- a/blocks/procedures.js
+++ b/blocks/procedures.js
@@ -214,7 +214,7 @@ Blockly.Blocks['procedures_defnoreturn'] = {
     this.paramIds_ = [];
     this.argumentVarModels_ = [];
     var paramBlock = containerBlock.getInputTargetBlock('STACK');
-    while (paramBlock) {
+    while (paramBlock && !paramBlock.isInsertionMarker()) {
       var varName = paramBlock.getFieldValue('NAME');
       this.arguments_.push(varName);
       var variable = this.workspace.getVariable(varName, '');
diff --git a/blocks/text.js b/blocks/text.js
index 65710f1aa..9e806be92 100644
--- a/blocks/text.js
+++ b/blocks/text.js
@@ -722,7 +722,7 @@ Blockly.Constants.Text.TEXT_JOIN_MUTATOR_MIXIN = {
     var itemBlock = containerBlock.getInputTargetBlock('STACK');
     // Count number of inputs.
     var connections = [];
-    while (itemBlock) {
+    while (itemBlock && !itemBlock.isInsertionMarker()) {
       connections.push(itemBlock.valueConnection_);
       itemBlock = itemBlock.nextConnection &&
           itemBlock.nextConnection.targetBlock();