diff --git a/extlib/xfile b/extlib/xfile
index 0b01b3ea..476dadc8 160000
--- a/extlib/xfile
+++ b/extlib/xfile
@@ -1 +1 @@
-Subproject commit 0b01b3eab320022f8aef2f6982e0178d3061e89c
+Subproject commit 476dadc8f243488791acda8a6ecc208c4f4b95a7
diff --git a/include/picrin.h b/include/picrin.h
index 4aedbb40..9edf3826 100644
--- a/include/picrin.h
+++ b/include/picrin.h
@@ -210,7 +210,7 @@ void pic_warn(pic_state *, const char *);
 const char *pic_errmsg(pic_state *);
 
 pic_value pic_debug(pic_state *, pic_value);
-pic_value pic_fdebug(pic_state *, pic_value, XFILE *);
+pic_value pic_fdebug(pic_state *, pic_value, xFILE *);
 
 #if defined(__cplusplus)
 }
diff --git a/include/picrin/port.h b/include/picrin/port.h
index dd346d90..9fabf8ed 100644
--- a/include/picrin/port.h
+++ b/include/picrin/port.h
@@ -23,7 +23,7 @@ enum pic_port_status {
 
 struct pic_port {
   PIC_OBJECT_HEADER
-  XFILE *file;
+  xFILE *file;
   int flags;
   int status;
 };
diff --git a/include/picrin/string.h b/include/picrin/string.h
index 6fd5b32b..5dc81bf1 100644
--- a/include/picrin/string.h
+++ b/include/picrin/string.h
@@ -32,7 +32,7 @@ int pic_strcmp(pic_state *, pic_str *, pic_str *);
 
 pic_value pic_format(pic_state *, const char *, ...);
 pic_value pic_vformat(pic_state *, const char *, va_list);
-pic_value pic_vfformat(pic_state *, XFILE *, const char *, va_list);
+pic_value pic_vfformat(pic_state *, xFILE *, const char *, va_list);
 
 #if defined(__cplusplus)
 }
diff --git a/src/file.c b/src/file.c
index c68a1869..8f55a4d1 100644
--- a/src/file.c
+++ b/src/file.c
@@ -9,7 +9,7 @@ static pic_value
 generic_open_file(pic_state *pic, const char *fname, char *mode, short flags)
 {
   struct pic_port *port;
-  XFILE *file;
+  xFILE *file;
 
   file = xfopen(fname, mode);
   if (! file) {
diff --git a/src/port.c b/src/port.c
index 2f460d82..ae40285a 100644
--- a/src/port.c
+++ b/src/port.c
@@ -43,7 +43,7 @@ pic_stdout(pic_state *pic)
 }
 
 static pic_value
-port_new_stdport(pic_state *pic, XFILE *file, short dir)
+port_new_stdport(pic_state *pic, xFILE *file, short dir)
 {
   struct pic_port *port;
 
diff --git a/src/string.c b/src/string.c
index 9b0004d3..b6345ed0 100644
--- a/src/string.c
+++ b/src/string.c
@@ -112,7 +112,7 @@ pic_strcmp(pic_state *pic, pic_str *str1, pic_str *str2)
 }
 
 pic_value
-pic_vfformat(pic_state *pic, XFILE *file, const char *fmt, va_list ap)
+pic_vfformat(pic_state *pic, xFILE *file, const char *fmt, va_list ap)
 {
   char c;
   pic_value irrs = pic_nil_value();
diff --git a/src/write.c b/src/write.c
index 80756369..3adcda38 100644
--- a/src/write.c
+++ b/src/write.c
@@ -44,14 +44,14 @@ is_quasiquote(pic_state *pic, pic_value pair)
 
 struct writer_control {
   pic_state *pic;
-  XFILE *file;
+  xFILE *file;
   xhash *labels;
   xhash *visited;
   int cnt;
 };
 
 static struct writer_control *
-writer_control_new(pic_state *pic, XFILE *file)
+writer_control_new(pic_state *pic, xFILE *file)
 {
   struct writer_control *p;
 
@@ -152,7 +152,7 @@ write_pair(struct writer_control *p, struct pic_pair *pair)
 }
 
 static void
-write_str(pic_state *pic, struct pic_string *str, XFILE *file)
+write_str(pic_state *pic, struct pic_string *str, xFILE *file)
 {
   size_t i;
   const char *cstr = str->str;
@@ -171,7 +171,7 @@ static void
 write_core(struct writer_control *p, pic_value obj)
 {
   pic_state *pic = p->pic;
-  XFILE *file = p->file;
+  xFILE *file = p->file;
   size_t i;
   xh_entry *e;
 
@@ -316,7 +316,7 @@ write_core(struct writer_control *p, pic_value obj)
 }
 
 static void
-write(pic_state *pic, pic_value obj, XFILE *file)
+write(pic_state *pic, pic_value obj, xFILE *file)
 {
   struct writer_control *p;
 
@@ -330,7 +330,7 @@ write(pic_state *pic, pic_value obj, XFILE *file)
 }
 
 static void
-write_simple(pic_state *pic, pic_value obj, XFILE *file)
+write_simple(pic_state *pic, pic_value obj, xFILE *file)
 {
   struct writer_control *p;
 
@@ -344,7 +344,7 @@ write_simple(pic_state *pic, pic_value obj, XFILE *file)
 }
 
 static void
-write_shared(pic_state *pic, pic_value obj, XFILE *file)
+write_shared(pic_state *pic, pic_value obj, xFILE *file)
 {
   struct writer_control *p;
 
@@ -364,7 +364,7 @@ pic_debug(pic_state *pic, pic_value obj)
 }
 
 pic_value
-pic_fdebug(pic_state *pic, pic_value obj, XFILE *file)
+pic_fdebug(pic_state *pic, pic_value obj, xFILE *file)
 {
   write(pic, obj, file);
   xfflush(file);