diff --git a/include/tidy.h b/include/tidy.h
index 2f3dabd..bca1463 100755
--- a/include/tidy.h
+++ b/include/tidy.h
@@ -631,6 +631,9 @@ TIDY_EXPORT Bool TIDY_CALL tidyInitSink( TidyOutputSink* sink,
 TIDY_EXPORT void TIDY_CALL tidyPutByte( TidyOutputSink* sink, uint byteValue );
 
 
+/****************
+   Errors
+****************/
 /** Callback to filter messages by diagnostic level:
 **  info, warning, etc.  Just set diagnostic output 
 **  handler to redirect all diagnostics output.  Return true
@@ -656,6 +659,18 @@ TIDY_EXPORT int TIDY_CALL     tidySetErrorBuffer( TidyDoc tdoc, TidyBuffer* errb
 /** Set error sink to given generic sink */
 TIDY_EXPORT int TIDY_CALL     tidySetErrorSink( TidyDoc tdoc, TidyOutputSink* sink );
 
+
+/****************
+   Printing
+****************/
+/** Callback to track the progress of the pretting printing process.
+**
+*/
+typedef Bool (TIDY_CALL *TidyPPProgress)( TidyDoc tdoc, uint line, uint col, uint destLine );
+
+TIDY_EXPORT Bool TIDY_CALL   tidySetPrettyPrinterCallback( TidyDoc tdoc,
+                                                  TidyPPProgress callback );
+
 /** @} end IO group */
 
 /* TODO: Catalog all messages for easy translation
diff --git a/src/pprint.c b/src/pprint.c
index 2411156..c42d2fc 100644
--- a/src/pprint.c
+++ b/src/pprint.c
@@ -2118,10 +2118,17 @@ void TY_(PPrintTree)( TidyDocImpl* doc, uint mode, uint indent, Node *node )
     Node *content, *last;
     uint spaces = cfg( doc, TidyIndentSpaces );
     Bool xhtml = cfgBool( doc, TidyXhtmlOut );
+    uint lastline = 0;
 
     if ( node == NULL )
         return;
 
+    if (doc->progressCallback)
+    {
+        if (doc->pprint.line > lastline)
+            doc->progressCallback( tidyImplToDoc(doc), node->line, node->column, doc->pprint.line );
+    }
+
     if (node->type == TextNode)
     {
         PPrintText( doc, mode, indent, node );
diff --git a/src/tidy-int.h b/src/tidy-int.h
index f4a4703..51bcf3b 100755
--- a/src/tidy-int.h
+++ b/src/tidy-int.h
@@ -59,6 +59,7 @@ struct _TidyDocImpl
     TidyReportFilter    mssgFilt;
     TidyReportFilter2   mssgFilt2;
     TidyOptCallback     pOptCallback;
+    TidyPPProgress      progressCallback;
 
     /* Parse + Repair Results */
     uint                optionErrors;
diff --git a/src/tidylib.c b/src/tidylib.c
index 0d7dc88..851a752 100755
--- a/src/tidylib.c
+++ b/src/tidylib.c
@@ -752,6 +752,19 @@ int TIDY_CALL    tidySetErrorSink( TidyDoc tdoc, TidyOutputSink* sink )
     return -EINVAL;
 }
 
+/* Use TidyPPProgress to monitor the progress of the pretty printer.
+ */
+Bool TIDY_CALL        tidySetPrettyPrinterCallback(TidyDoc tdoc, TidyPPProgress callback)
+{
+    TidyDocImpl* impl = tidyDocToImpl( tdoc );
+    if ( impl )
+    {
+        impl->progressCallback = callback;
+        return yes;
+    }
+    return no;
+}
+
 
 /* Document info */
 int TIDY_CALL        tidyStatus( TidyDoc tdoc )