diff --git a/mozilla/modules/calendar/src/libcal/util/julnstr.cpp b/mozilla/modules/calendar/src/libcal/util/julnstr.cpp
index 2c0f9984f46..574de849d58 100644
--- a/mozilla/modules/calendar/src/libcal/util/julnstr.cpp
+++ b/mozilla/modules/calendar/src/libcal/util/julnstr.cpp
@@ -30,6 +30,10 @@
 #include "nspr.h"
 #include "plstr.h"
 
+#if 0
+/* Breaks SINIX5.4 build */
+#include <npapi.h>
+#endif
 #include "jdefines.h"
 #include "julnstr.h"