diff --git a/eeschema/pin_number.cpp b/eeschema/pin_number.cpp
index 440fe7c3cc..85b8dfeb79 100644
--- a/eeschema/pin_number.cpp
+++ b/eeschema/pin_number.cpp
@@ -23,6 +23,7 @@
  */
 
 #include "pin_number.h"
+#include <wx/crt.h>
 
 namespace {