diff --git a/fs/efi.c b/fs/efi.c
index 0f74cda..83c4682 100644
--- a/fs/efi.c
+++ b/fs/efi.c
@@ -32,6 +32,7 @@
 #include <efi.h>
 #include <mach/efi.h>
 #include <mach/efi-device.h>
+#include <linux/stddef.h>
 
 /* Open modes */
 #define EFI_FILE_MODE_READ      0x0000000000000001
@@ -92,8 +93,6 @@
 	s16 FileName[1];
 };
 
-typedef unsigned short wchar_t;
-
 struct efifs_priv {
 	struct efi_file_handle *root_dir;
 	struct efi_file_io_interface *protocol;
diff --git a/include/linux/stddef.h b/include/linux/stddef.h
index e366328..680d0c7 100644
--- a/include/linux/stddef.h
+++ b/include/linux/stddef.h
@@ -17,6 +17,8 @@
 #include <linux/types.h>
 #endif
 
+typedef unsigned short wchar_t;
+
 #undef offsetof
 #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
 
diff --git a/include/wchar.h b/include/wchar.h
index 702d8e2..adb4f37 100644
--- a/include/wchar.h
+++ b/include/wchar.h
@@ -2,8 +2,7 @@
 #define __WCHAR_H
 
 #include <linux/types.h>
-
-typedef u16 wchar_t;
+#include <linux/stddef.h>
 
 wchar_t *strdup_wchar(const wchar_t *src);