diff --git a/datasette/utils/__init__.py b/datasette/utils/__init__.py
index 44641a87..70ac8976 100644
--- a/datasette/utils/__init__.py
+++ b/datasette/utils/__init__.py
@@ -1080,11 +1080,12 @@ class StartupError(Exception):
 
 _re_named_parameter = re.compile(":([a-zA-Z0-9_]+)")
 
+
 async def derive_named_parameters(db, sql):
-    explain = 'explain {}'.format(sql.strip().rstrip(";"))
+    explain = "explain {}".format(sql.strip().rstrip(";"))
     possible_params = _re_named_parameter.findall(sql)
     try:
         results = await db.execute(explain, {p: None for p in possible_params})
         return [row["p4"].lstrip(":") for row in results if row["opcode"] == "Variable"]
     except sqlite3.DatabaseError:
-        return []
+        return possible_params
diff --git a/tests/test_utils.py b/tests/test_utils.py
index e04efb4b..e1b61072 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -629,13 +629,16 @@ def test_parse_metadata(content, expected):
 
 
 @pytest.mark.asyncio
-@pytest.mark.parametrize("sql,expected", (
-    ("select 1", []),
-    ("select 1 + :one", ["one"]),
-    ("select 1 + :one + :two", ["one", "two"]),
-    ("select 'bob' || '0:00' || :cat", ["cat"]),
-    ("select this is invalid", []),
-))
+@pytest.mark.parametrize(
+    "sql,expected",
+    (
+        ("select 1", []),
+        ("select 1 + :one", ["one"]),
+        ("select 1 + :one + :two", ["one", "two"]),
+        ("select 'bob' || '0:00' || :cat", ["cat"]),
+        ("select this is invalid :one, :two, :three", ["one", "two", "three"]),
+    ),
+)
 async def test_derive_named_parameters(sql, expected):
     ds = Datasette([], memory=True)
     db = ds.get_database("_memory")