diff --git a/ChangeLog b/ChangeLog
index 7f9cb69a01..9547a499d6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,18 @@
+Wed Mar  6 01:19:28 2013  Kazuhiro NISHIYAMA  <zn@mbf.nifty.com>
+
+	* enumerator.c (enumerator_with_index, lazy_take): use INT2FIX(0)
+	  instead of INT2NUM(0).
+
+	* ext/bigdecimal/bigdecimal.c (BigMath_s_exp): ditto.
+
+	* ext/fiddle/function.c (function_call): ditto.
+
+	* ext/openssl/ossl_x509store.c (ossl_x509store_initialize): ditto.
+
+	* process.c (proc_getsid): ditto.
+
+	* transcode.c (econv_finish): ditto.
+
 Tue Mar  5 21:36:43 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* class.c (rb_prepend_module): check redefinition of built-in optimized
diff --git a/enumerator.c b/enumerator.c
index 7143e37636..022690a2a3 100644
--- a/enumerator.c
+++ b/enumerator.c
@@ -493,7 +493,7 @@ enumerator_with_index(int argc, VALUE *argv, VALUE obj)
     rb_scan_args(argc, argv, "01", &memo);
     RETURN_SIZED_ENUMERATOR(obj, argc, argv, enumerator_size);
     if (NIL_P(memo))
-	memo = INT2NUM(0);
+	memo = INT2FIX(0);
     return enumerator_block_call(obj, enumerator_with_index_i, (VALUE)&memo);
 }
 
@@ -1742,7 +1742,7 @@ lazy_take(VALUE obj, VALUE n)
 	rb_raise(rb_eArgError, "attempt to take negative size");
     }
     if (len == 0) {
-	VALUE len = INT2NUM(0);
+	VALUE len = INT2FIX(0);
 	lazy = lazy_to_enum_i(obj, sym_cycle, 1, &len, 0);
     }
     else {
diff --git a/ext/bigdecimal/bigdecimal.c b/ext/bigdecimal/bigdecimal.c
index dfb5daa527..414f124c44 100644
--- a/ext/bigdecimal/bigdecimal.c
+++ b/ext/bigdecimal/bigdecimal.c
@@ -2669,7 +2669,7 @@ BigMath_s_exp(VALUE klass, VALUE x, VALUE vprec)
     }
     if (infinite) {
 	if (negative) {
-	    return ToValue(GetVpValueWithPrec(INT2NUM(0), prec, 1));
+	    return ToValue(GetVpValueWithPrec(INT2FIX(0), prec, 1));
 	}
 	else {
 	    Real* vy;
diff --git a/ext/fiddle/function.c b/ext/fiddle/function.c
index c184c78663..72a1a6238d 100644
--- a/ext/fiddle/function.c
+++ b/ext/fiddle/function.c
@@ -135,9 +135,9 @@ function_call(int argc, VALUE argv[], VALUE self)
 
 	if(NUM2INT(type) == TYPE_VOIDP) {
 	    if(NIL_P(src)) {
-		src = INT2NUM(0);
+		src = INT2FIX(0);
 	    } else if(cPointer != CLASS_OF(src)) {
-	        src = rb_funcall(cPointer, rb_intern("[]"), 1, src);
+		src = rb_funcall(cPointer, rb_intern("[]"), 1, src);
 	    }
 	    src = rb_Integer(src);
 	}
diff --git a/ext/openssl/ossl_x509store.c b/ext/openssl/ossl_x509store.c
index 5e3094ee9f..2afa0cf595 100644
--- a/ext/openssl/ossl_x509store.c
+++ b/ext/openssl/ossl_x509store.c
@@ -135,9 +135,9 @@ ossl_x509store_initialize(int argc, VALUE *argv, VALUE self)
     ossl_x509store_set_vfy_cb(self, Qnil);
 
 #if (OPENSSL_VERSION_NUMBER < 0x00907000L)
-    rb_iv_set(self, "@flags", INT2NUM(0));
-    rb_iv_set(self, "@purpose", INT2NUM(0));
-    rb_iv_set(self, "@trust", INT2NUM(0));
+    rb_iv_set(self, "@flags", INT2FIX(0));
+    rb_iv_set(self, "@purpose", INT2FIX(0));
+    rb_iv_set(self, "@trust", INT2FIX(0));
 #endif
 
     /* last verification status */
diff --git a/process.c b/process.c
index 34a38cb18e..48eee5dc75 100644
--- a/process.c
+++ b/process.c
@@ -4248,7 +4248,7 @@ proc_getsid(int argc, VALUE *argv)
     rb_scan_args(argc, argv, "01", &pid);
 
     if (NIL_P(pid))
-	pid = INT2NUM(0);
+	pid = INT2FIX(0);
 
     sid = getsid(NUM2PIDT(pid));
     if (sid < 0) rb_sys_fail(0);
diff --git a/transcode.c b/transcode.c
index de9edf866a..de12c04f0f 100644
--- a/transcode.c
+++ b/transcode.c
@@ -3864,7 +3864,7 @@ econv_finish(VALUE self)
     av[1] = dst;
     av[2] = Qnil;
     av[3] = Qnil;
-    av[4] = INT2NUM(0);
+    av[4] = INT2FIX(0);
     ac = 5;
 
     ret = econv_primitive_convert(ac, av, self);