diff --git a/lib/mixins/pool.js b/lib/mixins/pool.js
index 5d83ade..ade2a20 100644
--- a/lib/mixins/pool.js
+++ b/lib/mixins/pool.js
@@ -12,7 +12,7 @@ module.exports = class Pool {
     const Singular = capitalize(singular)
     const Plural = capitalize(plural)
 
-    const source = `class ${Plural}Pool extends Mixin {
+    const source = `(class ${Plural}Pool extends Mixin {
       init${Plural}Pool (${plural}Class, ${plural}Container) {
         this.${plural}Class = ${plural}Class
         this.${plural}Container = ${plural}Container
@@ -56,12 +56,10 @@ module.exports = class Pool {
         this.used${Plural} = []
         return this.unused${Plural} = []
       }
-    }`
+    })`
 
     const sandbox = {Mixin, atom, console}
-    const context = vm.createContext(sandbox)
-
-    const mixin = vm.runInContext(source, context, `${plural}-pool.vm`)
+    const mixin = vm.runInNewContext(source, sandbox, `${plural}-pool.vm`)
     mixin.includeInto(this)
   }
 }
diff --git a/lib/table-element.js b/lib/table-element.js
index 81b9bee..19d7e12 100644
--- a/lib/table-element.js
+++ b/lib/table-element.js
@@ -1306,8 +1306,10 @@ class TableElement extends HTMLElement {
     const cursorValue = cursor.getValue()
     this.editor.setText(String(cursorValue || this.getUndefinedDisplay()))
 
-    this.editor.getBuffer().history.clearUndoStack()
-    this.editor.getBuffer().history.clearRedoStack()
+    if(this.editor.getBuffer().history != undefined){
+      this.editor.getBuffer().history.clearUndoStack()
+      this.editor.getBuffer().history.clearRedoStack()
+    }
 
     if (initialData) { this.editor.setText(initialData) }
   }