diff --git a/tests/strings/unicode.cpp b/tests/strings/unicode.cpp
index 9ddaba42cd..2abae879ac 100644
--- a/tests/strings/unicode.cpp
+++ b/tests/strings/unicode.cpp
@@ -18,6 +18,7 @@
 #endif
 
 #ifndef WX_PRECOMP
+    #include "wx/wx.h"
 #endif // WX_PRECOMP
 
 // ----------------------------------------------------------------------------