diff --git a/lib/linguist/documentation.yml b/lib/linguist/documentation.yml
index b884cd35..a2578040 100644
--- a/lib/linguist/documentation.yml
+++ b/lib/linguist/documentation.yml
@@ -10,7 +10,8 @@
 ## Documentation Conventions ##
 
 - ^docs?/
-- ^Documentation/
+- ^[Dd]ocumentation/
+- ^man/
 
 - (^|/)CONTRIBUTING(\.|$)
 - (^|/)COPYING(\.|$)
diff --git a/test/test_blob.rb b/test/test_blob.rb
index d59e6794..6c071420 100644
--- a/test/test_blob.rb
+++ b/test/test_blob.rb
@@ -448,7 +448,12 @@ class TestBlob < Minitest::Test
     refute_predicate fixture_blob("project/docs/foo.html"), :documentation?
 
     assert_predicate fixture_blob("Documentation/foo.md"), :documentation?
+    assert_predicate fixture_blob("documentation/foo.md"), :documentation?
     refute_predicate fixture_blob("project/Documentation/foo.md"), :documentation?
+    refute_predicate fixture_blob("project/documentation/foo.md"), :documentation?
+
+    assert_predicate fixture_blob("man/foo.html"), :documentation?
+    refute_predicate fixture_blob("project/man/foo.html"), :documentation?
 
     assert_predicate fixture_blob("README"), :documentation?
     assert_predicate fixture_blob("README.md"), :documentation?