1 files changed, 6 insertions, 2 deletions
diff --git a/spec/ruby/library/date/constants_spec.rb b/spec/ruby/library/date/constants_spec.rb
index 8e564fe665..ae343f07ec 100644
--- a/spec/ruby/library/date/constants_spec.rb
+++ b/spec/ruby/library/date/constants_spec.rb
@@ -34,9 +34,13 @@ describe "Date constants" do
 
   it "freezes MONTHNAMES, DAYNAMES, ABBR_MONTHNAMES, ABBR_DAYSNAMES" do
     [Date::MONTHNAMES, Date::DAYNAMES, Date::ABBR_MONTHNAMES, Date::ABBR_DAYNAMES].each do |ary|
-      lambda { ary << "Unknown" }.should raise_error
+      lambda {
+        ary << "Unknown"
+      }.should raise_error(RuntimeError, /frozen/)
       ary.compact.each do |name|
-        lambda { name << "modified" }.should raise_error
+        lambda {
+          name << "modified"
+        }.should raise_error(RuntimeError, /frozen/)
       end
     end
   end