diff --git a/src/mac/cdef/extcdef.c b/src/mac/cdef/extcdef.c
new file mode 100644
index 0000000000..0e21b457a1
--- /dev/null
+++ b/src/mac/cdef/extcdef.c
@@ -0,0 +1,29 @@
+#include "extcdef.h"  
+
+/*************************************************************************
+
+	main
+
+*************************************************************************/
+
+pascal SInt32 main(SInt16 varCode , ControlHandle theControl , ControlDefProcMessage message, SInt32 param )
+{
+	long	returnValue = 0L;
+	char	state = HGetState((Handle)theControl);
+	
+	if ( message != initCntl )
+	{
+		ExtCDEFInfo* info = (ExtCDEFInfo* )  (**theControl).contrlRfCon ;
+		if ( info )
+		{
+			returnValue =	info->defProc( info->procID, theControl, message, param) ;
+		}
+	}
+	else
+	{
+		 (**theControl).contrlRfCon = NULL ;
+	}
+	HSetState((Handle)theControl,state);
+
+	return(returnValue);				/* tell them what happened */
+}
diff --git a/src/mac/cdef/extcdef.h b/src/mac/cdef/extcdef.h
new file mode 100644
index 0000000000..2c7bf88d3b
--- /dev/null
+++ b/src/mac/cdef/extcdef.h
@@ -0,0 +1,21 @@
+#pragma once
+
+#include <stdlib.h>
+ 
+#define kExtCDEFID 128	// resource id of our CDEF resource <Controls.h>
+const long kExtCDEFMagic = 0xFEEDFEED ; 
+typedef struct ExtCDEFInfo
+{
+	ControlDefProcPtr		defProc ; // this must always be the lowest element
+	long								magic ;
+	long								contrlRfCon ;
+	ControlHandle				containerControl ;
+	Handle							children ;
+	ControlFontStyleRec fontStyle ;
+	Boolean							hasFocus ;
+	SInt16							procID ;
+	long								privateData ;
+} ExtCDEFInfo ;
+
+void NewExtCDEFInfo( ControlHandle theControl , ControlDefProcPtr defproc , SInt16 procID , long refcon ) ;
+void DisposeExtCDEFInfo( ControlHandle theControl) ;
diff --git a/src/mac/cdef/extcdef.mcp b/src/mac/cdef/extcdef.mcp
new file mode 100644
index 0000000000..ecd61b8d7f
Binary files /dev/null and b/src/mac/cdef/extcdef.mcp differ