diff --git a/unix/Makefile b/unix/Makefile
index a24962a291..785e53c0ac 100644
--- a/unix/Makefile
+++ b/unix/Makefile
@@ -157,8 +157,8 @@ LIB_SRC_C = $(addprefix lib/,\
 
 # FatFS VFS support
 LIB_SRC_C += $(addprefix lib/,\
-	fatfs/ff.c \
-	fatfs/option/ccsbcs.c \
+	oofatfs/ff.c \
+	oofatfs/option/unicode.c \
 	)
 
 OBJ = $(PY_O)
diff --git a/unix/mpconfigport.h b/unix/mpconfigport.h
index eb46565464..ce026310c3 100644
--- a/unix/mpconfigport.h
+++ b/unix/mpconfigport.h
@@ -131,6 +131,7 @@
 #define MICROPY_MACHINE_MEM_GET_READ_ADDR   mod_machine_mem_get_addr
 #define MICROPY_MACHINE_MEM_GET_WRITE_ADDR  mod_machine_mem_get_addr
 
+#define MICROPY_FATFS_OO               (1)
 #define MICROPY_FATFS_ENABLE_LFN       (1)
 #define MICROPY_FATFS_RPATH            (2)
 // Can't have less than 3 values because diskio.h uses volume numbers