diff --git a/include/wx/stringops.h b/include/wx/stringops.h
index 972b832717..2cfbe188e4 100644
--- a/include/wx/stringops.h
+++ b/include/wx/stringops.h
@@ -15,6 +15,7 @@
 #include "wx/chartype.h"
 #include "wx/stringimpl.h"
 #include "wx/unichar.h"
+#include "wx/buffer.h"
 
 // This header contains wxStringOperations "namespace" class that implements
 // elementary operations on string data as static methods; wxString methods and