--- a
+++ b/tests/unit/docs/test_schemas.py
@@ -0,0 +1,44 @@
+import pytest
+
+from ehrql.docs.schemas import get_table_docstring
+from ehrql.tables import EventFrame, Series, table
+
+
+def test_get_table_docstring():
+    @table
+    class parent_table(EventFrame):
+        "I have a docstring"
+
+        col_a = Series(str)
+
+    @table
+    class child_table(parent_table.__class__):
+        """
+        I have a docstring
+
+        With some extra stuff
+        """
+
+        col_b = Series(str)
+
+    assert (
+        get_table_docstring(child_table.__class__)
+        == "I have a docstring\n\nWith some extra stuff"
+    )
+
+
+def test_get_table_docstring_with_mismatch():
+    @table
+    class parent_table(EventFrame):
+        "I have a docstring"
+
+        col_a = Series(str)
+
+    @table
+    class child_table(parent_table.__class__):
+        "I have a different docstring"
+
+        col_b = Series(str)
+
+    with pytest.raises(ValueError):
+        get_table_docstring(child_table.__class__)