diff --git a/changelog/4649.bugfix.rst b/changelog/4649.bugfix.rst
new file mode 100644
index 000000000..74b241781
--- /dev/null
+++ b/changelog/4649.bugfix.rst
@@ -0,0 +1 @@
+Restore marks being considered keywords for keyword expressions.
diff --git a/src/_pytest/mark/legacy.py b/src/_pytest/mark/legacy.py
index cea136bff..f784ffa20 100644
--- a/src/_pytest/mark/legacy.py
+++ b/src/_pytest/mark/legacy.py
@@ -45,13 +45,14 @@ class KeywordMapping(object):
                 mapped_names.add(item.name)
 
         # Add the names added as extra keywords to current or parent items
-        for name in item.listextrakeywords():
-            mapped_names.add(name)
+        mapped_names.update(item.listextrakeywords())
 
         # Add the names attached to the current function through direct assignment
         if hasattr(item, "function"):
-            for name in item.function.__dict__:
-                mapped_names.add(name)
+            mapped_names.update(item.function.__dict__)
+
+        # add the markers to the keywords as we no longer handle them correctly
+        mapped_names.update(mark.name for mark in item.iter_markers())
 
         return cls(mapped_names)
 
diff --git a/testing/example_scripts/marks/marks_considered_keywords/conftest.py b/testing/example_scripts/marks/marks_considered_keywords/conftest.py
new file mode 100644
index 000000000..e69de29bb
diff --git a/testing/example_scripts/marks/marks_considered_keywords/test_marks_as_keywords.py b/testing/example_scripts/marks/marks_considered_keywords/test_marks_as_keywords.py
new file mode 100644
index 000000000..35a2c7b76
--- /dev/null
+++ b/testing/example_scripts/marks/marks_considered_keywords/test_marks_as_keywords.py
@@ -0,0 +1,6 @@
+import pytest
+
+
+@pytest.mark.foo
+def test_mark():
+    pass
diff --git a/testing/test_mark.py b/testing/test_mark.py
index a10e2e19d..f7d8cf689 100644
--- a/testing/test_mark.py
+++ b/testing/test_mark.py
@@ -292,6 +292,13 @@ def test_keyword_option_custom(spec, testdir):
     assert list(passed) == list(passed_result)
 
 
+def test_keyword_option_considers_mark(testdir):
+    testdir.copy_example("marks/marks_considered_keywords")
+    rec = testdir.inline_run("-k", "foo")
+    passed = rec.listoutcomes()[0]
+    assert len(passed) == 1
+
+
 @pytest.mark.parametrize(
     "spec",
     [