diff --git a/app/lib/link_checker/uri_checker/http_checker.rb b/app/lib/link_checker/uri_checker/http_checker.rb
index c4558320..4da6df66 100644
--- a/app/lib/link_checker/uri_checker/http_checker.rb
+++ b/app/lib/link_checker/uri_checker/http_checker.rb
@@ -53,6 +53,12 @@ def initialize(options = {})
     end
   end
 
+  class PageBlocksBots < LinkChecker::UriChecker::Warning
+    def initialize(options = {})
+      super(summary: :page_blocks_bots, message: :page_blocked_bots, **options)
+    end
+  end
+
   class PageRequiresLogin < Error
     def initialize(options = {})
       super(summary: :page_requires_login, message: :login_required_to_view, **options)
@@ -172,7 +178,11 @@ def check_request
       if response.status == 404 || response.status == 410
         add_problem(PageNotFound.new(from_redirect: from_redirect?))
       elsif response.status == 401 || response.status == 403
-        add_problem(PageRequiresLogin.new(from_redirect: from_redirect?))
+        if response.headers["cf-mitigated"] == "challenge"
+          add_problem(PageBlocksBots.new(from_redirect: from_redirect?))
+        else
+          add_problem(PageRequiresLogin.new(from_redirect: from_redirect?))
+        end
       elsif response.status >= 400 && response.status < 500
         add_problem(PageIsUnavailable.new(from_redirect: from_redirect?, status: response.status))
       elsif response.status >= 500 && response.status < 600
diff --git a/app/lib/link_checker/uri_checker/problem.rb b/app/lib/link_checker/uri_checker/problem.rb
index c32072c6..29bf4158 100644
--- a/app/lib/link_checker/uri_checker/problem.rb
+++ b/app/lib/link_checker/uri_checker/problem.rb
@@ -47,6 +47,7 @@ def get_string(symbol)
       NoHost
       HttpCommunicationError
       PageNotFound
+      PageBlocksBots
       PageRequiresLogin
       PageIsUnavailable
       PageRespondsWithError
diff --git a/config/locales/en.yml b/config/locales/en.yml
index a408432e..bab6c1e8 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -64,6 +64,11 @@ en:
     redirect: This redirects to a page not found (404).
   find_content_now: Find where the content is now hosted and link to that instead.
 
+  page_blocks_bots: Page blocks robots
+  page_blocked_bots:
+    singular: Our link checker was blocked from accessing the website.
+    redirect: This redirects to a page that blocked our link checker from accessing the website.
+
   page_requires_login: Page requires login
   login_required_to_view:
     singular: A login is required to view this page.
diff --git a/spec/lib/link_checker_spec.rb b/spec/lib/link_checker_spec.rb
index 4c767613..764cb2c3 100644
--- a/spec/lib/link_checker_spec.rb
+++ b/spec/lib/link_checker_spec.rb
@@ -10,9 +10,10 @@
       end
     end
 
-    shared_examples "has errors" do
+    shared_examples "has errors" do |error = nil|
       it "should have errors" do
         expect(subject.errors).to_not be_empty
+        expect(subject.errors).to include(error) if error
       end
     end
 
@@ -22,9 +23,10 @@
       end
     end
 
-    shared_examples "has warnings" do
+    shared_examples "has warnings" do |warning = nil|
       it "should have warnings" do
         expect(subject.warnings).to_not be_empty
+        expect(subject.warnings).to include(warning) if warning
       end
     end
 
@@ -202,42 +204,56 @@
     context "401 status code" do
       let(:uri) { "http://www.not-gov.uk/401" }
       before { stub_request(:get, uri).to_return(status: 401) }
-      include_examples "has errors", "401 error (page requires login)"
+      include_examples "has errors", "A login is required to view this page."
       include_examples "has no warnings"
     end
 
-    context "403 status code" do
+    context "403 status code with Cloudflare challenge header" do
+      let(:uri) { "http://www.not-gov.uk/403" }
+      before do
+        stub_request(:get, uri).to_return(
+          status: 403,
+          headers: {
+            "cf-mitigated" => "challenge",
+          },
+        )
+      end
+      include_examples "has no errors"
+      include_examples "has warnings", "Our link checker was blocked from accessing the website."
+    end
+
+    context "403 status code without Cloudflare challenge header" do
       let(:uri) { "http://www.not-gov.uk/403" }
       before { stub_request(:get, uri).to_return(status: 403) }
-      include_examples "has errors", "403 error (page requires login)"
+      include_examples "has errors", "A login is required to view this page."
       include_examples "has no warnings"
     end
 
     context "404 status code" do
       let(:uri) { "http://www.not-gov.uk/404" }
       before { stub_request(:get, uri).to_return(status: 404) }
-      include_examples "has errors", "404 error (page not found)"
+      include_examples "has errors", "This page was not found (404)."
       include_examples "has no warnings"
     end
 
     context "410 status code" do
       let(:uri) { "http://www.not-gov.uk/410" }
       before { stub_request(:get, uri).to_return(status: 410) }
-      include_examples "has errors", "410 error (page not found)"
+      include_examples "has errors", "This page was not found (404)."
       include_examples "has no warnings"
     end
 
     context "an unspecified 4xx status code" do
       let(:uri) { "http://www.not-gov.uk/418" }
       before { stub_request(:get, uri).to_return(status: 418) }
-      include_examples "has errors", "418 error (page is unavailable)"
+      include_examples "has errors", "This page is unavailable (418)."
       include_examples "has no warnings"
     end
 
     context "5xx status code" do
       let(:uri) { "http://www.not-gov.uk/500" }
       before { stub_request(:get, uri).to_return(status: 500) }
-      include_examples "has errors", "500 (server error)"
+      include_examples "has errors", "This page is responding with an error (500) and won't work for users."
       include_examples "has no warnings"
     end