diff --git a/ChangeLog b/ChangeLog
index 0a607d4b0f..1bd107ab16 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Mon Mar  1 20:07:06 2010  TAKANO Mitsuhiro (takano32)  <tak@no32.tk>
+
+	* ext/zlib/zlib.c (zstream_expand_buffer_into): remove compare different type values warning.
+
 Mon Mar  1 17:42:45 2010  wanabe  <s.wanabe@gmail.com>
 
 	* configure.in (mingw): do not detect snprintf/vsnprintf.
diff --git a/ext/zlib/zlib.c b/ext/zlib/zlib.c
index 3c50b99785..435a1a6a9f 100644
--- a/ext/zlib/zlib.c
+++ b/ext/zlib/zlib.c
@@ -59,7 +59,7 @@ struct zstream;
 struct zstream_funcs;
 static void zstream_init(struct zstream*, const struct zstream_funcs*);
 static void zstream_expand_buffer(struct zstream*);
-static void zstream_expand_buffer_into(struct zstream*, int);
+static void zstream_expand_buffer_into(struct zstream*, unsigned int);
 static void zstream_append_buffer(struct zstream*, const Bytef*, int);
 static VALUE zstream_detach_buffer(struct zstream*);
 static VALUE zstream_shift_buffer(struct zstream*, int);
@@ -518,7 +518,7 @@ zstream_expand_buffer(struct zstream *z)
 }
 
 static void
-zstream_expand_buffer_into(struct zstream *z, int size)
+zstream_expand_buffer_into(struct zstream *z, unsigned int size)
 {
     if (NIL_P(z->buf)) {
 	/* I uses rb_str_new here not rb_str_buf_new because
@@ -2591,7 +2591,7 @@ rb_gzfile_set_mtime(VALUE obj, VALUE mtime)
     }
     else {
 	val = rb_Integer(mtime);
-	gz->mtime = FIXNUM_P(val) ? FIX2INT(val) : rb_big2ulong(val);
+	gz->mtime = FIXNUM_P(val) ? FIX2UINT(val) : rb_big2ulong(val);
     }
     return mtime;
 }