diff --git a/lib/ostruct.rb b/lib/ostruct.rb
index fa882b7..c762baa 100644
--- a/lib/ostruct.rb
+++ b/lib/ostruct.rb
@@ -376,7 +376,7 @@ def delete_field(name, &block)
     end
     @table.delete(sym) do
       return yield if block
-      raise! NameError.new("no field `#{sym}' in #{self}", sym)
+      raise! NameError.new("no field '#{sym}' in #{self}", sym)
     end
   end