diff --git a/src/common/memory.cpp b/src/common/memory.cpp
index f31d76136f..a2ad41e444 100644
--- a/src/common/memory.cpp
+++ b/src/common/memory.cpp
@@ -27,6 +27,7 @@
     #include "wx/app.h"
     #include "wx/hash.h"
     #include "wx/log.h"
+    #include "wx/wxcrtvararg.h" // for wxVsnprintf 
 #endif
 
 #if wxUSE_THREADS
diff --git a/src/x11/font.cpp b/src/x11/font.cpp
index a20332d680..dd818e5c4c 100644
--- a/src/x11/font.cpp
+++ b/src/x11/font.cpp
@@ -35,6 +35,7 @@
     #include "wx/utils.h"       // for wxGetDisplay()
     #include "wx/settings.h"
     #include "wx/gdicmn.h"
+    #include "wx/wxcrtvararg.h" // for wxSscanf
 #endif
 
 #include "wx/fontutil.h"    // for wxNativeFontInfo