diff --git a/stmhal/Makefile b/stmhal/Makefile
index bd00667624663e09022efa86df26e1e446f7644a..3cad7d1da4cd9a4f47aeda87fc81b2851be132ed 100644
--- a/stmhal/Makefile
+++ b/stmhal/Makefile
@@ -154,6 +154,7 @@ SRC_C = \
 	flash.c \
 	storage.c \
 	file.c \
+	builtin_open.c \
 	sdcard.c \
 	diskio.c \
 	fatfs_port.c \
diff --git a/stmhal/builtin_open.c b/stmhal/builtin_open.c
new file mode 100644
index 0000000000000000000000000000000000000000..c7e183f91bea4b89307fd1ceccb041bdecdcc074
--- /dev/null
+++ b/stmhal/builtin_open.c
@@ -0,0 +1,30 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2013, 2014 Damien P. George
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "py/runtime.h"
+#include "file.h"
+
+MP_DEFINE_CONST_FUN_OBJ_KW(mp_builtin_open_obj, 1, fatfs_builtin_open);
diff --git a/stmhal/file.c b/stmhal/file.c
index a61fa050cfaf16c52abd52c26b37bbc4a4b9badf..b3e811231ac54d706d345c5982de9e06025354ff 100644
--- a/stmhal/file.c
+++ b/stmhal/file.c
@@ -271,10 +271,9 @@ const mp_obj_type_t mp_type_textio = {
 };
 
 // Factory function for I/O stream classes
-mp_obj_t mp_builtin_open(mp_uint_t n_args, const mp_obj_t *args, mp_map_t *kwargs) {
+mp_obj_t fatfs_builtin_open(mp_uint_t n_args, const mp_obj_t *args, mp_map_t *kwargs) {
     // TODO: analyze buffering args and instantiate appropriate type
     mp_arg_val_t arg_vals[FILE_OPEN_NUM_ARGS];
     mp_arg_parse_all(n_args, args, kwargs, FILE_OPEN_NUM_ARGS, file_open_args, arg_vals);
     return file_open(&mp_type_textio, arg_vals);
 }
-MP_DEFINE_CONST_FUN_OBJ_KW(mp_builtin_open_obj, 1, mp_builtin_open);
diff --git a/stmhal/file.h b/stmhal/file.h
index f21ec6dab6b6a3e73b604d1099ab8e873f120c10..e62fd826f67709e104a9e3ee60092fc50244b6e4 100644
--- a/stmhal/file.h
+++ b/stmhal/file.h
@@ -26,4 +26,5 @@
 
 extern const byte fresult_to_errno_table[20];
 
+mp_obj_t fatfs_builtin_open(mp_uint_t n_args, const mp_obj_t *args, mp_map_t *kwargs);
 MP_DECLARE_CONST_FUN_OBJ(mp_builtin_open_obj);