1 files changed, 1 insertions, 2 deletions
diff --git a/lib/ostruct.rb b/lib/ostruct.rb
index 09d81b8a5a..b49df2d2d6 100644
--- a/lib/ostruct.rb
+++ b/lib/ostruct.rb
@@ -170,8 +170,7 @@ class OpenStruct
     begin
       @modifiable = true
     rescue
-      exception_class = defined?(FrozenError) ? FrozenError : RuntimeError
-      raise exception_class, "can't modify frozen #{self.class}", caller(3)
+      raise FrozenError, "can't modify frozen #{self.class}", caller(3)
     end
     @table
   end