diff --git a/samples/dialup/nettest.cpp b/samples/dialup/nettest.cpp
index c5e727bf5e..7e31dad045 100644
--- a/samples/dialup/nettest.cpp
+++ b/samples/dialup/nettest.cpp
@@ -35,6 +35,10 @@
     #include "wx/wx.h"
 #endif
 
+#if !wxUSE_DIALUP_MANAGER
+#error You must set wxUSE_DIALUP_MANAGER to 1 in setup.h!
+#endif
+
 #include "wx/dialup.h"
 
 // ----------------------------------------------------------------------------
diff --git a/samples/joytest/joytest.cpp b/samples/joytest/joytest.cpp
index 5fe4889958..a073793928 100644
--- a/samples/joytest/joytest.cpp
+++ b/samples/joytest/joytest.cpp
@@ -20,8 +20,12 @@
 #include "wx/wx.h"
 #endif
 
-#include <wx/wave.h>
-#include <wx/joystick.h>
+#if !wxUSE_JOYSTICK
+#error You must set wxUSE_JOYSTICK to 1 in setup.h!
+#endif
+
+#include "wx/wave.h"
+#include "wx/joystick.h"
 
 #include "joytest.h"