diff --git a/spec/addressable/uri_spec.rb b/spec/addressable/uri_spec.rb
index 9ab8038e..4b41a775 100644
--- a/spec/addressable/uri_spec.rb
+++ b/spec/addressable/uri_spec.rb
@@ -1061,7 +1061,8 @@ def to_s
   end
 
   it "should not allow destructive operations" do
-    expect { @uri.normalize! }.to raise_error(FrozenError)
+    has_frozen_error = Gem::Version.new(RUBY_VERSION) < Gem::Version.new('2.5.0')
+    expect { @uri.normalize! }.to raise_error(has_frozen_error ? RuntimeError : FrozenError)
   end
 end