diff --git a/lib/capybara/selector/definition/frame.rb b/lib/capybara/selector/definition/frame.rb
index 70649b40e..f5e26639d 100644
--- a/lib/capybara/selector/definition/frame.rb
+++ b/lib/capybara/selector/definition/frame.rb
@@ -5,7 +5,7 @@
     xpath = XPath.descendant(:iframe).union(XPath.descendant(:frame))
     unless locator.nil?
       locator_matchers = (XPath.attr(:id) == locator.to_s) | (XPath.attr(:name) == locator.to_s)
-      locator_matchers |= XPath.attr(test_id) == locator if test_id
+      locator_matchers |= XPath.attr(test_id) == locator.to_s if test_id
       xpath = xpath[locator_matchers]
     end
     xpath[find_by_attr(:name, name)]
diff --git a/lib/capybara/selector/definition/label.rb b/lib/capybara/selector/definition/label.rb
index ff6d764e2..bd3baff0d 100644
--- a/lib/capybara/selector/definition/label.rb
+++ b/lib/capybara/selector/definition/label.rb
@@ -6,7 +6,7 @@
     xpath = XPath.descendant(:label)
     unless locator.nil?
       locator_matchers = XPath.string.n.is(locator.to_s) | (XPath.attr(:id) == locator.to_s)
-      locator_matchers |= XPath.attr(test_id) == locator if test_id
+      locator_matchers |= XPath.attr(test_id) == locator.to_s if test_id
       xpath = xpath[locator_matchers]
     end
     if options.key?(:for)
diff --git a/lib/capybara/selector/definition/table.rb b/lib/capybara/selector/definition/table.rb
index b93f4812f..d5d41888a 100644
--- a/lib/capybara/selector/definition/table.rb
+++ b/lib/capybara/selector/definition/table.rb
@@ -5,7 +5,7 @@
     xpath = XPath.descendant(:table)
     unless locator.nil?
       locator_matchers = (XPath.attr(:id) == locator.to_s) | XPath.descendant(:caption).is(locator.to_s)
-      locator_matchers |= XPath.attr(test_id) == locator if test_id
+      locator_matchers |= XPath.attr(test_id) == locator.to_s if test_id
       xpath = xpath[locator_matchers]
     end
     xpath = xpath[XPath.descendant(:caption) == caption] if caption