diff --git a/ChangeLog b/ChangeLog
index 61691ba939..f312ea69f1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Mon Nov 26 10:44:20 2007  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* io.c (rb_read_internal, rb_sysopen_internal): remove C99 dependency.
+
 Sun Nov 25 22:21:35 2007  Tanaka Akira  <akr@fsij.org>
 
 	* include/ruby/encoding.h (rb_enc_str_asciionly_p): declared.
diff --git a/io.c b/io.c
index 1bc8064700..ce1472ece0 100644
--- a/io.c
+++ b/io.c
@@ -919,7 +919,10 @@ read_func(void *ptr)
 static int
 rb_read_internal(int fd, void *buf, size_t count)
 {
-    struct read_struct rs = {fd, buf, count};
+    struct read_struct rs;
+    rs.fd = fd;
+    rs.buf = buf;
+    rs.capa = count;
     return rb_thread_blocking_region(read_func, &rs, RB_UBF_DFL, 0);
 }
 
@@ -3049,7 +3052,10 @@ sysopen_func(void *ptr)
 static int
 rb_sysopen_internal(char *fname, int flags, unsigned int mode)
 {
-    struct sysopen_struct data = {fname, flags, mode};
+    struct sysopen_struct data;
+    data.fname = fname;
+    data.flag = flags;
+    data.mode = mode;
     return (int)rb_thread_blocking_region(sysopen_func, &data, RB_UBF_DFL, 0);
 }