diff --git a/mozilla/modules/plugin/samples/default/os2/dialogs.cpp b/mozilla/modules/plugin/samples/default/os2/dialogs.cpp
index b5d64a88e5f..f1f856cc8fa 100644
--- a/mozilla/modules/plugin/samples/default/os2/dialogs.cpp
+++ b/mozilla/modules/plugin/samples/default/os2/dialogs.cpp
@@ -38,6 +38,7 @@
 #define INCL_WIN
 #include <os2.h>
 #include <string.h>
+#include <assert.h>
 
 #include "npnulos2.h"
 
diff --git a/mozilla/modules/plugin/samples/default/os2/npshell.cpp b/mozilla/modules/plugin/samples/default/os2/npshell.cpp
index d3f2240d07d..9bc0ebbb7cd 100644
--- a/mozilla/modules/plugin/samples/default/os2/npshell.cpp
+++ b/mozilla/modules/plugin/samples/default/os2/npshell.cpp
@@ -37,6 +37,7 @@
 
 #include <os2.h>
 #include <string.h>
+#include <assert.h>
 
 #include "npnulos2.h"
 
diff --git a/mozilla/modules/plugin/samples/default/os2/plugin.cpp b/mozilla/modules/plugin/samples/default/os2/plugin.cpp
index 65b012143bc..fd12eb306bb 100644
--- a/mozilla/modules/plugin/samples/default/os2/plugin.cpp
+++ b/mozilla/modules/plugin/samples/default/os2/plugin.cpp
@@ -39,6 +39,8 @@
 #define INCL_WIN
 #include <os2.h>
 #include <string.h>
+#include <stdio.h>
+#include <assert.h>
 
 #include "npnulos2.h"