diff --git a/ChangeLog b/ChangeLog
index 6d3325667..886085f70 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2009-06-01  suzuki toshiya  <mpsuzuki@hiroshima-u.ac.jp>
+
+	Keep existing modules.cfg in the building tree.
+
+	* configure: When configure is executed out of the source tree,
+	existing modules.cfg in building directory should be kept as
+	the building in the source tree.
+
 2009-06-27  suzuki toshiya  <mpsuzuki@hiroshima-u.ac.jp>
 
 	Filter --srcdir= option before invoking builds/unix/configure.
diff --git a/configure b/configure
index 008aa3e54..6382f5fcb 100644
--- a/configure
+++ b/configure
@@ -82,8 +82,10 @@ fi
 
 if test "$abs_curr_dir" != "$abs_ft2_dir"; then
   mkdir reference
-  echo "Copying \`modules.cfg'"
-  cp $abs_ft2_dir/modules.cfg $abs_curr_dir
+  if test ! -r $abs_curr_dir/modules.cfg; then
+    echo "Copying \`modules.cfg'"
+    cp $abs_ft2_dir/modules.cfg $abs_curr_dir
+  fi
   echo "Generating \`Makefile'"
   echo "TOP_DIR   := $abs_ft2_dir"               > Makefile
   echo "OBJ_DIR   := $abs_curr_dir"             >> Makefile