diff --git a/npapi/npapi.h b/npapi/npapi.h
index e5baad9..507b723 100644
--- a/npapi/npapi.h
+++ b/npapi/npapi.h
@@ -379,7 +379,7 @@ typedef enum {
   , NPPVpluginCoreAnimationLayer = 1003
 #endif
 
-#if (MOZ_PLATFORM_MAEMO == 5) || (MOZ_PLATFORM_MAEMO == 6)
+#if defined(MOZ_PLATFORM_MAEMO) && ((MOZ_PLATFORM_MAEMO == 5) || (MOZ_PLATFORM_MAEMO == 6))
   , NPPVpluginWindowlessLocalBool = 2002
 #endif
 } NPPVariable;
@@ -434,7 +434,7 @@ typedef enum {
   , NPNVsupportsCompositingCoreAnimationPluginsBool = 74656 /* TRUE if the browser supports
                                                                CA model compositing */
 #endif
-#if (MOZ_PLATFORM_MAEMO == 5) || (MOZ_PLATFORM_MAEMO == 6)
+#if defined(MOZ_PLATFORM_MAEMO) && ((MOZ_PLATFORM_MAEMO == 5) || (MOZ_PLATFORM_MAEMO == 6))
   , NPNVSupportsWindowlessLocal = 2002
 #endif
 } NPNVariable;