diff --git a/mozilla/base/src/nsInputStream.cpp b/mozilla/base/src/nsInputStream.cpp
index ba15de987ad..1e7bd9aa2d1 100644
--- a/mozilla/base/src/nsInputStream.cpp
+++ b/mozilla/base/src/nsInputStream.cpp
@@ -20,6 +20,7 @@
 #include <fcntl.h>
 #ifdef XP_PC
 #include <io.h>
+#include <windows.h>
 #else
 #include <unistd.h>
 #endif