diff --git a/Source/Bind/DocProcessor.cs b/Source/Bind/DocProcessor.cs
index fcd69f9b..57afe0cd 100644
--- a/Source/Bind/DocProcessor.cs
+++ b/Source/Bind/DocProcessor.cs
@@ -14,6 +14,9 @@ namespace Bind
         static readonly XslCompiledTransform xslt = new XslCompiledTransform();
         static readonly XmlReaderSettings settings = new XmlReaderSettings();
 
+        string Text;
+        string LastFile;
+
         public DocProcessor(string transform_file)
         {
             xslt.Load(transform_file);
@@ -27,35 +30,40 @@ namespace Bind
         // Todo: Some files include more than 1 function - find a way to map these extra functions.
         public string ProcessFile(string file)
         {
-            string text = File.ReadAllText(file);
+            if (LastFile == file)
+                return Text;
 
-            Match m = remove_mathml.Match(text);
+            LastFile = file;
+            Text = File.ReadAllText(file);
+
+            Match m = remove_mathml.Match(Text);
             while (m.Length > 0)
             {
-                string removed = text.Substring(m.Index, m.Length);
-                text = text.Remove(m.Index, m.Length);
+                string removed = Text.Substring(m.Index, m.Length);
+                Text = Text.Remove(m.Index, m.Length);
                 int equation = removed.IndexOf("eqn");
                 if (equation > 0)
                 {
-                    text = text.Insert(m.Index,
+                    Text = Text.Insert(m.Index,
                         "<![CDATA[" +
                         removed.Substring(equation + 4, removed.IndexOf(":-->") - equation - 4) +
                         "]]>");
                 }
-                m = remove_mathml.Match(text);
+                m = remove_mathml.Match(Text);
             }
 
             XmlReader doc = null;
             try
             {
                 // The pure XmlReader is ~20x faster than the XmlTextReader.
-                doc = XmlReader.Create(new StringReader(text), settings);
+                doc = XmlReader.Create(new StringReader(Text), settings);
                 //doc = new XmlTextReader(new StringReader(text));
                 
                 using (StringWriter sw = new StringWriter())
                 {
                     xslt.Transform(doc, null, sw);
-                    return sw.ToString().TrimEnd('\n');
+                    Text = sw.ToString().TrimEnd('\n');
+                    return Text;
                 }
             }
             catch (XmlException e)