diff --git a/ChangeLog b/ChangeLog
index e596647dd6..6a22165df5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Fri Jan 28 12:05:48 2011  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
+
+	* configure.in: Add #include<sys/stat.h> when struct stat is
+	  tested. Otherwise, incomplete type dereference error will occur.
+
 Fri Jan 28 11:53:19 2011  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
 
 	* configure.in: redundant variable names made strange conftest
diff --git a/configure.in b/configure.in
index 8e1bc3b6e4..25f1bbd726 100644
--- a/configure.in
+++ b/configure.in
@@ -1149,7 +1149,7 @@ RUBY_CHECK_PRINTF_PREFIX(ptrdiff_t, t)
 AC_STRUCT_ST_BLKSIZE
 AC_STRUCT_ST_BLOCKS
 AC_STRUCT_ST_RDEV
-RUBY_CHECK_SIZEOF([struct stat.st_size], [int long "long long"])
+RUBY_CHECK_SIZEOF([struct stat.st_size], [int long "long long"], [], [@%:@include <sys/stat.h>])
 if test "$ac_cv_member_struct_stat_st_blocks" = yes; then
     RUBY_CHECK_SIZEOF([struct stat.st_blocks], [int long "long long"])
 fi