3 files changed, 5 insertions, 13 deletions
diff --git a/Modules/_sqlite/connection.c b/Modules/_sqlite/connection.c
index 0d6462e..5ceeaf9 100644
--- a/Modules/_sqlite/connection.c
+++ b/Modules/_sqlite/connection.c
@@ -1223,7 +1223,7 @@ PyObject* pysqlite_connection_call(pysqlite_Connection* self, PyObject* args, Py
     if (!_PyArg_NoKeywords(MODULE_NAME ".Connection", kwargs))
         return NULL;
 
-    if (!PyArg_ParseTuple(args, "O", &sql))
+    if (!PyArg_ParseTuple(args, "U", &sql))
         return NULL;
 
     _pysqlite_drop_unused_statement_references(self);
diff --git a/Modules/_sqlite/cursor.c b/Modules/_sqlite/cursor.c
index 01b9dc4..38d94b2 100644
--- a/Modules/_sqlite/cursor.c
+++ b/Modules/_sqlite/cursor.c
@@ -384,12 +384,7 @@ _pysqlite_query_execute(pysqlite_Cursor* self, int multiple, PyObject* args)
 
     if (multiple) {
         /* executemany() */
-        if (!PyArg_ParseTuple(args, "OO", &operation, &second_argument)) {
-            goto error;
-        }
-
-        if (!PyUnicode_Check(operation)) {
-            PyErr_SetString(PyExc_ValueError, "operation parameter must be str");
+        if (!PyArg_ParseTuple(args, "UO", &operation, &second_argument)) {
             goto error;
         }
 
@@ -406,12 +401,7 @@ _pysqlite_query_execute(pysqlite_Cursor* self, int multiple, PyObject* args)
         }
     } else {
         /* execute() */
-        if (!PyArg_ParseTuple(args, "O|O", &operation, &second_argument)) {
-            goto error;
-        }
-
-        if (!PyUnicode_Check(operation)) {
-            PyErr_SetString(PyExc_ValueError, "operation parameter must be str");
+        if (!PyArg_ParseTuple(args, "U|O", &operation, &second_argument)) {
             goto error;
         }
 
diff --git a/Modules/_sqlite/statement.c b/Modules/_sqlite/statement.c
index 491294b..9de8f9b 100644
--- a/Modules/_sqlite/statement.c
+++ b/Modules/_sqlite/statement.c
@@ -59,6 +59,8 @@ int pysqlite_statement_create(pysqlite_Statement* self, pysqlite_Connection* con
     self->st = NULL;
     self->in_use = 0;
 
+    assert(PyUnicode_Check(sql));
+
     sql_cstr = PyUnicode_AsUTF8AndSize(sql, &sql_cstr_len);
     if (sql_cstr == NULL) {
         rc = PYSQLITE_SQL_WRONG_TYPE;