diff --git a/spec/docile_spec.rb b/spec/docile_spec.rb
index e912f9b..b9e3ea8 100644
--- a/spec/docile_spec.rb
+++ b/spec/docile_spec.rb
@@ -249,7 +249,7 @@ def push_element
           expect { push_element }.
             to raise_error(
               NoMethodError,
-              /undefined method `push' (for|on) nil:NilClass/
+              /undefined method `push' (for|on) nil/
             )
         end
       end