diff --git a/lib/rails/dom/testing/assertions/selector_assertions/html_selector.rb b/lib/rails/dom/testing/assertions/selector_assertions/html_selector.rb
index 0e2227b..7e927ce 100644
--- a/lib/rails/dom/testing/assertions/selector_assertions/html_selector.rb
+++ b/lib/rails/dom/testing/assertions/selector_assertions/html_selector.rb
@@ -52,7 +52,7 @@ def filter(matches)
       content.sub!(/\A\n/, '') if text_matches && match.name == "textarea"
 
       next if regex_matching ? (content =~ match_with) : (content == match_with)
-      content_mismatch ||= sprintf("<%s> expected but was\n<%s>.", match_with, content)
+      content_mismatch ||= sprintf("<%s> expected but was\n<%s>", match_with, content)
       true
     end