diff --git a/ChangeLog b/ChangeLog
index 41bad13aa9..fd4e086281 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Sat Feb 25 11:08:28 2012  Tanaka Akira  <akr@fsij.org>
+
+	* ext/curses/curses.c (Init_curses): use rb_define_const once for
+	  Curses::VERSION.
+
+	* ext/dbm/dbm.c (Init_dbm): ditto for DBM::VERSION.
+
 Sat Feb 25 10:34:22 2012  Tanaka Akira  <akr@fsij.org>
 
 	* ext/curses/curses.c (Init_curses): make Curses::VERSION
diff --git a/ext/curses/curses.c b/ext/curses/curses.c
index 69dc09cf30..20f23d188b 100644
--- a/ext/curses/curses.c
+++ b/ext/curses/curses.c
@@ -2768,20 +2768,22 @@ Init_curses(void)
     rb_define_module_function(mCurses, "def_prog_mode", curses_def_prog_mode, 0);
     rb_define_module_function(mCurses, "reset_prog_mode", curses_reset_prog_mode, 0);
 
-#if defined(HAVE_FUNC_CURSES_VERSION)
-    /* ncurses and PDcurses */
-    rb_define_const(mCurses, "VERSION", rb_str_new2(curses_version()));
-#elif defined(HAVE_VAR_CURSES_VERSION)
     {
+        VALUE version;
+#if defined(HAVE_FUNC_CURSES_VERSION)
+        /* ncurses and PDcurses */
+        version = rb_str_new2(curses_version());
+#elif defined(HAVE_VAR_CURSES_VERSION)
         /* SVR4 curses has an undocumented and undeclared variable, curses_version.
          * It contains a string, "SVR4".  */
         RUBY_EXTERN char *curses_version;
-        rb_define_const(mCurses, "VERSION", rb_sprintf("curses (%s)", curses_version));
-    }
+        version = rb_sprintf("curses (%s)", curses_version);
 #else
-    /* BSD curses, perhaps.  NetBSD 5 still use it. */ 
-    rb_define_const(mCurses, "VERSION", rb_str_new2("curses (unknown)"));
+        /* BSD curses, perhaps.  NetBSD 5 still use it. */ 
+        version = rb_str_new2("curses (unknown)");
 #endif
+        rb_define_const(mCurses, "VERSION", version);
+    }
 
     /*
      * Document-class: Curses::Window
diff --git a/ext/dbm/dbm.c b/ext/dbm/dbm.c
index f220d3e7c0..e0640d9638 100644
--- a/ext/dbm/dbm.c
+++ b/ext/dbm/dbm.c
@@ -1085,36 +1085,38 @@ Init_dbm(void)
      */
     rb_define_const(rb_cDBM, "NEWDB",   INT2FIX(O_RDWR|O_CREAT|O_TRUNC|RUBY_DBM_RW_BIT));
 
+    {
+        VALUE version;
 #if defined(_DBM_IOERR)
-    rb_define_const(rb_cDBM, "VERSION",  rb_str_new2("ndbm (4.3BSD)"));
+        version = rb_str_new2("ndbm (4.3BSD)");
 #elif defined(RUBYDBM_GDBM_HEADER)
 #  if defined(HAVE_DECLARED_LIBVAR_GDBM_VERSION)
-    /* since gdbm 1.9 */
-    rb_define_const(rb_cDBM, "VERSION",  rb_str_new2(gdbm_version));
+        /* since gdbm 1.9 */
+        version = rb_str_new2(gdbm_version);
 #  elif defined(HAVE_UNDECLARED_LIBVAR_GDBM_VERSION)
-    /* ndbm.h doesn't declare gdbm_version until gdbm 1.8.3.
-     * See extconf.rb for more information. */
-    {
-	RUBY_EXTERN char *gdbm_version;
-	rb_define_const(rb_cDBM, "VERSION",  rb_str_new2(gdbm_version));
-    }
+        /* ndbm.h doesn't declare gdbm_version until gdbm 1.8.3.
+         * See extconf.rb for more information. */
+        RUBY_EXTERN char *gdbm_version;
+        version = rb_str_new2(gdbm_version);
 #  else
-    rb_define_const(rb_cDBM, "VERSION",  rb_str_new2("GDBM (unknown)"));
+        version = rb_str_new2("GDBM (unknown)");
 #  endif
 #elif defined(RUBYDBM_DB_HEADER)
 #  if defined(HAVE_DB_VERSION)
-    /* The version of the dbm library, if using Berkeley DB */
-    rb_define_const(rb_cDBM, "VERSION",  rb_str_new2(db_version(NULL, NULL, NULL)));
+        /* The version of the dbm library, if using Berkeley DB */
+        version = rb_str_new2(db_version(NULL, NULL, NULL));
 #  else
-    rb_define_const(rb_cDBM, "VERSION",  rb_str_new2("Berkeley DB (unknown)"));
+        version = rb_str_new2("Berkeley DB (unknown)");
 #  endif
 #elif defined(_RELIC_H)
 #  if defined(HAVE_DPVERSION)
-    rb_define_const(rb_cDBM, "VERSION",  rb_sprintf("QDBM %s", dpversion));
+        version = rb_sprintf("QDBM %s", dpversion);
 #  else
-    rb_define_const(rb_cDBM, "VERSION",  rb_str_new2("QDBM (unknown)"));
+        version = rb_str_new2("QDBM (unknown)");
 #  endif
 #else
-    rb_define_const(rb_cDBM, "VERSION",  rb_str_new2("ndbm (unknown)"));
+        version = rb_str_new2("ndbm (unknown)");
 #endif
+        rb_define_const(rb_cDBM, "VERSION", version);
+    }
 }