diff --git a/tests/test_write_sql.py b/tests/test_write_sql.py
deleted file mode 100644
index 75d6b6e1..00000000
--- a/tests/test_write_sql.py
+++ /dev/null
@@ -1,71 +0,0 @@
-from datasette.utils.sql_analysis import Operation
-from datasette.write_sql import (
-    IgnoreWriteSqlOperation,
-    RejectWriteSqlOperation,
-    RequireWriteSqlPermissions,
-    UnsupportedWriteSqlOperation,
-    decision_for_write_sql_operation,
-)
-
-
-def test_decision_for_write_sql_operation_ignores_internal_operations():
-    decision = decision_for_write_sql_operation(
-        Operation("read", "schema", None, None, "main", internal=True)
-    )
-
-    assert isinstance(decision, IgnoreWriteSqlOperation)
-    assert decision.reason == "internal SQLite operation"
-
-
-def test_decision_for_write_sql_operation_ignores_select_statement_operations():
-    decision = decision_for_write_sql_operation(
-        Operation("select", "statement", None, None, None)
-    )
-
-    assert isinstance(decision, IgnoreWriteSqlOperation)
-    assert decision.reason == "select statement"
-
-
-def test_decision_for_write_sql_operation_requires_table_write_permissions():
-    decision = decision_for_write_sql_operation(
-        Operation("insert", "table", "data", "dogs", None)
-    )
-
-    assert isinstance(decision, RequireWriteSqlPermissions)
-    assert [permission.action for permission in decision.permissions] == [
-        "insert-row",
-        "update-row",
-        "delete-row",
-    ]
-    assert [str(permission.resource) for permission in decision.permissions] == [
-        "data/dogs",
-        "data/dogs",
-        "data/dogs",
-    ]
-
-
-def test_decision_for_write_sql_operation_rejects_vacuum():
-    decision = decision_for_write_sql_operation(
-        Operation("vacuum", "statement", None, None, None)
-    )
-
-    assert isinstance(decision, RejectWriteSqlOperation)
-    assert decision.message == "VACUUM is not allowed in user-supplied SQL"
-
-
-def test_decision_for_write_sql_operation_ignores_functions():
-    decision = decision_for_write_sql_operation(
-        Operation("function", "function", None, None, None, target="upper")
-    )
-
-    assert isinstance(decision, IgnoreWriteSqlOperation)
-    assert decision.reason == "SQL function"
-
-
-def test_decision_for_write_sql_operation_reports_unsupported_operations():
-    decision = decision_for_write_sql_operation(
-        Operation("unknown", "unknown", None, None, None)
-    )
-
-    assert isinstance(decision, UnsupportedWriteSqlOperation)
-    assert decision.message == "Unsupported SQL operation: unknown unknown"
diff --git a/tests/test_write_sql_operation_decisions.py b/tests/test_write_sql_operation_decisions.py
new file mode 100644
index 00000000..cc19f701
--- /dev/null
+++ b/tests/test_write_sql_operation_decisions.py
@@ -0,0 +1,94 @@
+import pytest
+
+from datasette.utils.sql_analysis import Operation
+from datasette.write_sql import (
+    IgnoreWriteSqlOperation,
+    RejectWriteSqlOperation,
+    RequireWriteSqlPermissions,
+    UnsupportedWriteSqlOperation,
+    decision_for_write_sql_operation,
+)
+
+
+@pytest.mark.parametrize(
+    ("operation", "reason"),
+    (
+        pytest.param(
+            Operation("read", "schema", None, None, "main", internal=True),
+            "internal SQLite operation",
+            id="internal",
+        ),
+        pytest.param(
+            Operation("select", "statement", None, None, None),
+            "select statement",
+            id="select-statement",
+        ),
+        pytest.param(
+            Operation("function", "function", None, None, None, target="upper"),
+            "SQL function",
+            id="function",
+        ),
+    ),
+)
+def test_decision_for_write_sql_operation_ignores_operations(operation, reason):
+    decision = decision_for_write_sql_operation(operation)
+
+    assert isinstance(decision, IgnoreWriteSqlOperation)
+    assert decision.reason == reason
+
+
+@pytest.mark.parametrize("operation", ("insert", "update"))
+def test_decision_for_write_sql_operation_requires_table_write_permissions(operation):
+    decision = decision_for_write_sql_operation(
+        Operation(operation, "table", "data", "dogs", None)
+    )
+
+    assert isinstance(decision, RequireWriteSqlPermissions)
+    assert [permission.action for permission in decision.permissions] == [
+        "insert-row",
+        "update-row",
+        "delete-row",
+    ]
+    assert [str(permission.resource) for permission in decision.permissions] == [
+        "data/dogs",
+        "data/dogs",
+        "data/dogs",
+    ]
+
+
+@pytest.mark.parametrize(
+    ("operation", "message"),
+    (
+        pytest.param(
+            Operation("vacuum", "statement", None, None, None),
+            "VACUUM is not allowed in user-supplied SQL",
+            id="vacuum",
+        ),
+        pytest.param(
+            Operation("insert", "table", "data", "docs", None, table_kind="virtual"),
+            "Writes to virtual tables are not allowed in user-supplied SQL",
+            id="virtual-table",
+        ),
+        pytest.param(
+            Operation(
+                "insert", "table", "data", "docs_data", None, table_kind="shadow"
+            ),
+            "Writes to shadow tables are not allowed in user-supplied SQL",
+            id="shadow-table",
+        ),
+    ),
+)
+def test_decision_for_write_sql_operation_rejects_operations(operation, message):
+    decision = decision_for_write_sql_operation(operation)
+
+    assert isinstance(decision, RejectWriteSqlOperation)
+    assert decision.message == message
+
+
+def test_decision_for_write_sql_operation_reports_unsupported_operations():
+    decision = decision_for_write_sql_operation(
+        Operation("unknown", "unknown", None, None, None)
+    )
+
+    assert isinstance(decision, UnsupportedWriteSqlOperation)
+    assert decision.message == "Unsupported SQL operation: unknown unknown"