diff --git a/Source/Ember/Variations01.h b/Source/Ember/Variations01.h
index 1c1a5a8..b59803d 100644
--- a/Source/Ember/Variations01.h
+++ b/Source/Ember/Variations01.h
@@ -6879,11 +6879,6 @@ public:
 		m_HalfScale = m_Scale / 2;
 	}
 
-	virtual vector<string> OpenCLGlobalFuncNames() const override
-	{
-		return vector<string> { "Zeps" };
-	}
-
 protected:
 	void Init()
 	{
diff --git a/Source/Fractorium/FractoriumEmberController.h b/Source/Fractorium/FractoriumEmberController.h
index d87d1bc..4f74f6c 100644
--- a/Source/Fractorium/FractoriumEmberController.h
+++ b/Source/Fractorium/FractoriumEmberController.h
@@ -33,7 +33,7 @@ template <typename T> class PreviewRenderer;
 template <typename T> class TreePreviewRenderer;
 
 #define PREVIEW_SIZE 256
-#define UNDO_SIZE 128
+#define UNDO_SIZE 512
 
 /// <summary>
 /// FractoriumEmberControllerBase serves as a non-templated base class with virtual
diff --git a/Source/Fractorium/FractoriumRender.cpp b/Source/Fractorium/FractoriumRender.cpp
index 92ca963..eb01881 100644
--- a/Source/Fractorium/FractoriumRender.cpp
+++ b/Source/Fractorium/FractoriumRender.cpp
@@ -458,7 +458,9 @@ bool FractoriumEmberController<T>::Render()
 					//else
 					//	qDebug() << "Mouse was down, not adding to undo list.";
 				}
-				else if (!m_LastEditWasUndoRedo && m_UndoIndex < m_UndoList.size() - 1)//They were anywhere but the end of the undo list, then did a manual edit, so clear the undo list.
+				else if (!m_LastEditWasUndoRedo &&
+						 m_UndoList.size() &&
+						 m_UndoIndex < m_UndoList.size() - 1)//They were anywhere but the end of the undo list, then did a manual edit, so clear the undo list.
 				{
 					Ember<T> ember(m_UndoList[m_UndoIndex]);
 					ClearUndo();