diff --git a/ext/date/date_core.c b/ext/date/date_core.c
index 251d025..7ab3fe6 100644
--- a/ext/date/date_core.c
+++ b/ext/date/date_core.c
@@ -7073,6 +7073,7 @@ strftimev(const char *fmt, VALUE self,
     (*func)(self, &tmx);
     len = date_strftime_alloc(&buf, fmt, &tmx);
     str = rb_usascii_str_new(buf, len);
+    str = rb_str_export_to_enc(str, rb_default_internal_encoding());
     if (buf != buffer) xfree(buf);
     return str;
 }
diff --git a/test/date/test_date.rb b/test/date/test_date.rb
index 86790e4..b4a1909 100644
--- a/test/date/test_date.rb
+++ b/test/date/test_date.rb
@@ -6,6 +6,22 @@ class DateTimeSub < DateTime; end
 
 class TestDate < Test::Unit::TestCase
 
+  def test_default_encoding
+    original = Encoding.default_internal
+    Encoding.default_internal = nil
+    assert_equal Encoding::US_ASCII, Date.today.to_s.encoding
+  ensure
+    Encoding.default_internal = original
+  end
+
+  def test_default_internal
+    original = Encoding.default_internal
+    Encoding.default_internal = Encoding::UTF_8
+    assert_equal Encoding::UTF_8, Date.today.to_s.encoding
+  ensure
+    Encoding.default_internal = original
+  end
+
   def test__const
     assert_nil(Date::MONTHNAMES[0])
     assert_equal('January', Date::MONTHNAMES[1])