diff --git a/common/common.cpp b/common/common.cpp
index cb62cf8dc7..2245ca433b 100644
--- a/common/common.cpp
+++ b/common/common.cpp
@@ -3,7 +3,7 @@
  *
  * Copyright (C) 2014-2015 Jean-Pierre Charras, jp.charras at wanadoo.fr
  * Copyright (C) 2008-2015 Wayne Stambaugh <stambaughw@verizon.net>
- * Copyright (C) 1992-2015 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 1992-2017 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -364,8 +364,10 @@ wxString GetOSXKicadDataDir()
 }
 #endif
 
-
+// add this only if it is not in wxWidgets (for instance before 3.1.0)
+#ifdef USE_KICAD_WXSTRING_HASH
 size_t std::hash<wxString>::operator()( const wxString& s ) const
 {
     return std::hash<std::wstring>{}( s.ToStdWstring() );
 }
+#endif
diff --git a/include/common.h b/include/common.h
index ad59b3338a..2f821ee538 100644
--- a/include/common.h
+++ b/include/common.h
@@ -337,6 +337,10 @@ wxString GetOSXKicadMachineDataDir();
 wxString GetOSXKicadDataDir();
 #endif
 
+// Some wxWidgets versions (for instance before 3.1.0) do not include
+// this function, so add it if missing
+#if !wxCHECK_VERSION( 3, 1, 0 )
+#define USE_KICAD_WXSTRING_HASH     // for common.cpp
 ///> Template specialization to enable wxStrings for certain containers (e.g. unordered_map)
 namespace std
 {
@@ -345,5 +349,6 @@ namespace std
         size_t operator()( const wxString& s ) const;
     };
 }
+#endif
 
 #endif  // INCLUDE__COMMON_H_