diff --git a/MAINTENANCE b/MAINTENANCE
index 202e93a..ce65c5f 100644
--- a/MAINTENANCE
+++ b/MAINTENANCE
@@ -9,8 +9,7 @@ tracked for changes (maintenance details below):
 Update code from https://github.com/mattn/go-sqlite3
 ----------------------------------------------------
 
-Current HEAD: 4c2df3cc4614a8001c1afdebcbda0fcf6e045719
-(from 2020-07-21)
+Current release: v1.14.5
 
 Use ./track_go-sqlite3.sh
 
diff --git a/callback.go b/callback.go
index 6450575..c3ce752 100644
--- a/callback.go
+++ b/callback.go
@@ -35,56 +35,55 @@ import (
 //export callbackTrampoline
 func callbackTrampoline(ctx *C.sqlite3_context, argc int, argv **C.sqlite3_value) {
 	args := (*[(math.MaxInt32 - 1) / unsafe.Sizeof((*C.sqlite3_value)(nil))]*C.sqlite3_value)(unsafe.Pointer(argv))[:argc:argc]
-	fi := lookupHandle(uintptr(C.sqlite3_user_data(ctx))).(*functionInfo)
+	fi := lookupHandle(C.sqlite3_user_data(ctx)).(*functionInfo)
 	fi.Call(ctx, args)
 }
 
 //export stepTrampoline
 func stepTrampoline(ctx *C.sqlite3_context, argc C.int, argv **C.sqlite3_value) {
 	args := (*[(math.MaxInt32 - 1) / unsafe.Sizeof((*C.sqlite3_value)(nil))]*C.sqlite3_value)(unsafe.Pointer(argv))[:int(argc):int(argc)]
-	ai := lookupHandle(uintptr(C.sqlite3_user_data(ctx))).(*aggInfo)
+	ai := lookupHandle(C.sqlite3_user_data(ctx)).(*aggInfo)
 	ai.Step(ctx, args)
 }
 
 //export doneTrampoline
 func doneTrampoline(ctx *C.sqlite3_context) {
-	handle := uintptr(C.sqlite3_user_data(ctx))
-	ai := lookupHandle(handle).(*aggInfo)
+	ai := lookupHandle(C.sqlite3_user_data(ctx)).(*aggInfo)
 	ai.Done(ctx)
 }
 
 //export compareTrampoline
-func compareTrampoline(handlePtr uintptr, la C.int, a *C.char, lb C.int, b *C.char) C.int {
+func compareTrampoline(handlePtr unsafe.Pointer, la C.int, a *C.char, lb C.int, b *C.char) C.int {
 	cmp := lookupHandle(handlePtr).(func(string, string) int)
 	return C.int(cmp(C.GoStringN(a, la), C.GoStringN(b, lb)))
 }
 
 //export commitHookTrampoline
-func commitHookTrampoline(handle uintptr) int {
+func commitHookTrampoline(handle unsafe.Pointer) int {
 	callback := lookupHandle(handle).(func() int)
 	return callback()
 }
 
 //export rollbackHookTrampoline
-func rollbackHookTrampoline(handle uintptr) {
+func rollbackHookTrampoline(handle unsafe.Pointer) {
 	callback := lookupHandle(handle).(func())
 	callback()
 }
 
 //export updateHookTrampoline
-func updateHookTrampoline(handle uintptr, op int, db *C.char, table *C.char, rowid int64) {
+func updateHookTrampoline(handle unsafe.Pointer, op int, db *C.char, table *C.char, rowid int64) {
 	callback := lookupHandle(handle).(func(int, string, string, int64))
 	callback(op, C.GoString(db), C.GoString(table), rowid)
 }
 
 //export authorizerTrampoline
-func authorizerTrampoline(handle uintptr, op int, arg1 *C.char, arg2 *C.char, arg3 *C.char) int {
+func authorizerTrampoline(handle unsafe.Pointer, op int, arg1 *C.char, arg2 *C.char, arg3 *C.char) int {
 	callback := lookupHandle(handle).(func(int, string, string, string) int)
 	return callback(op, C.GoString(arg1), C.GoString(arg2), C.GoString(arg3))
 }
 
 //export preUpdateHookTrampoline
-func preUpdateHookTrampoline(handle uintptr, dbHandle uintptr, op int, db *C.char, table *C.char, oldrowid int64, newrowid int64) {
+func preUpdateHookTrampoline(handle unsafe.Pointer, dbHandle uintptr, op int, db *C.char, table *C.char, oldrowid int64, newrowid int64) {
 	hval := lookupHandleVal(handle)
 	data := SQLitePreUpdateData{
 		Conn:         hval.db,
@@ -105,33 +104,27 @@ type handleVal struct {
 }
 
 var handleLock sync.Mutex
-var handleVals = make(map[uintptr]handleVal)
-var handleIndex uintptr = 100
+var handleVals = make(map[unsafe.Pointer]handleVal)
 
-func newHandle(db *SQLiteConn, v interface{}) uintptr {
+func newHandle(db *SQLiteConn, v interface{}) unsafe.Pointer {
 	handleLock.Lock()
 	defer handleLock.Unlock()
-	i := handleIndex
-	handleIndex++
-	handleVals[i] = handleVal{db, v}
-	return i
-}
-
-func lookupHandleVal(handle uintptr) handleVal {
-	handleLock.Lock()
-	defer handleLock.Unlock()
-	r, ok := handleVals[handle]
-	if !ok {
-		if handle >= 100 && handle < handleIndex {
-			panic("deleted handle")
-		} else {
-			panic("invalid handle")
-		}
+	val := handleVal{db: db, val: v}
+	var p unsafe.Pointer = C.malloc(C.size_t(1))
+	if p == nil {
+		panic("can't allocate 'cgo-pointer hack index pointer': ptr == nil")
 	}
-	return r
+	handleVals[p] = val
+	return p
 }
 
-func lookupHandle(handle uintptr) interface{} {
+func lookupHandleVal(handle unsafe.Pointer) handleVal {
+	handleLock.Lock()
+	defer handleLock.Unlock()
+	return handleVals[handle]
+}
+
+func lookupHandle(handle unsafe.Pointer) interface{} {
 	return lookupHandleVal(handle).val
 }
 
@@ -141,6 +134,7 @@ func deleteHandles(db *SQLiteConn) {
 	for handle, val := range handleVals {
 		if val.db == db {
 			delete(handleVals, handle)
+			C.free(handle)
 		}
 	}
 }
diff --git a/doc.go b/doc.go
index 682563e..ac27633 100644
--- a/doc.go
+++ b/doc.go
@@ -5,7 +5,7 @@ This works as a driver for database/sql.
 
 Installation
 
-    go get github.com/mutecomm/go-sqlcipher/v4
+    go get github.com/mattn/go-sqlite3
 
 Supported Types
 
@@ -79,9 +79,8 @@ Then, you can use this extension.
 
 Connection Hook
 
-You can hook and inject your code when the connection is established. database/sql
-doesn't provide a way to get native go-sqlite3 interfaces. So if you want,
-you need to set ConnectHook and get the SQLiteConn.
+You can hook and inject your code when the connection is established by setting
+ConnectHook to get the SQLiteConn.
 
 	sql.Register("sqlite3_with_hook_example",
 			&sqlite3.SQLiteDriver{
@@ -91,21 +90,45 @@ you need to set ConnectHook and get the SQLiteConn.
 					},
 			})
 
+You can also use database/sql.Conn.Raw (Go >= 1.13):
+
+	conn, err := db.Conn(context.Background())
+	// if err != nil { ... }
+	defer conn.Close()
+	err = conn.Raw(func (driverConn interface{}) error {
+		sqliteConn := driverConn.(*sqlite3.SQLiteConn)
+		// ... use sqliteConn
+	})
+	// if err != nil { ... }
+
 Go SQlite3 Extensions
 
-If you want to register Go functions as SQLite extension functions,
-call RegisterFunction from ConnectHook.
+If you want to register Go functions as SQLite extension functions
+you can make a custom driver by calling RegisterFunction from
+ConnectHook.
 
 	regex = func(re, s string) (bool, error) {
 		return regexp.MatchString(re, s)
 	}
-	sql.Register("sqlite3_with_go_func",
+	sql.Register("sqlite3_extended",
 			&sqlite3.SQLiteDriver{
 					ConnectHook: func(conn *sqlite3.SQLiteConn) error {
 						return conn.RegisterFunc("regexp", regex, true)
 					},
 			})
 
+You can then use the custom driver by passing its name to sql.Open.
+
+	var i int
+	conn, err := sql.Open("sqlite3_extended", "./foo.db")
+	if err != nil {
+		panic(err)
+	}
+	err = db.QueryRow(`SELECT regexp("foo.*", "seafood")`).Scan(&i)
+	if err != nil {
+		panic(err)
+	}
+
 See the documentation of RegisterFunc for more details.
 
 */
diff --git a/sqlite3.go b/sqlite3.go
index 8d7469b..33d4db9 100644
--- a/sqlite3.go
+++ b/sqlite3.go
@@ -473,7 +473,7 @@ func (c *SQLiteConn) RegisterCollation(name string, cmp func(string, string) int
 	handle := newHandle(c, cmp)
 	cname := C.CString(name)
 	defer C.free(unsafe.Pointer(cname))
-	rv := C.sqlite3_create_collation(c.db, cname, C.SQLITE_UTF8, unsafe.Pointer(handle), (*[0]byte)(unsafe.Pointer(C.compareTrampoline)))
+	rv := C.sqlite3_create_collation(c.db, cname, C.SQLITE_UTF8, handle, (*[0]byte)(unsafe.Pointer(C.compareTrampoline)))
 	if rv != C.SQLITE_OK {
 		return c.lastError()
 	}
@@ -491,7 +491,7 @@ func (c *SQLiteConn) RegisterCommitHook(callback func() int) {
 	if callback == nil {
 		C.sqlite3_commit_hook(c.db, nil, nil)
 	} else {
-		C.sqlite3_commit_hook(c.db, (*[0]byte)(C.commitHookTrampoline), unsafe.Pointer(newHandle(c, callback)))
+		C.sqlite3_commit_hook(c.db, (*[0]byte)(C.commitHookTrampoline), newHandle(c, callback))
 	}
 }
 
@@ -504,7 +504,7 @@ func (c *SQLiteConn) RegisterRollbackHook(callback func()) {
 	if callback == nil {
 		C.sqlite3_rollback_hook(c.db, nil, nil)
 	} else {
-		C.sqlite3_rollback_hook(c.db, (*[0]byte)(C.rollbackHookTrampoline), unsafe.Pointer(newHandle(c, callback)))
+		C.sqlite3_rollback_hook(c.db, (*[0]byte)(C.rollbackHookTrampoline), newHandle(c, callback))
 	}
 }
 
@@ -521,7 +521,7 @@ func (c *SQLiteConn) RegisterUpdateHook(callback func(int, string, string, int64
 	if callback == nil {
 		C.sqlite3_update_hook(c.db, nil, nil)
 	} else {
-		C.sqlite3_update_hook(c.db, (*[0]byte)(C.updateHookTrampoline), unsafe.Pointer(newHandle(c, callback)))
+		C.sqlite3_update_hook(c.db, (*[0]byte)(C.updateHookTrampoline), newHandle(c, callback))
 	}
 }
 
@@ -535,7 +535,7 @@ func (c *SQLiteConn) RegisterAuthorizer(callback func(int, string, string, strin
 	if callback == nil {
 		C.sqlite3_set_authorizer(c.db, nil, nil)
 	} else {
-		C.sqlite3_set_authorizer(c.db, (*[0]byte)(C.authorizerTrampoline), unsafe.Pointer(newHandle(c, callback)))
+		C.sqlite3_set_authorizer(c.db, (*[0]byte)(C.authorizerTrampoline), newHandle(c, callback))
 	}
 }
 
@@ -616,8 +616,8 @@ func (c *SQLiteConn) RegisterFunc(name string, impl interface{}, pure bool) erro
 	return nil
 }
 
-func sqlite3CreateFunction(db *C.sqlite3, zFunctionName *C.char, nArg C.int, eTextRep C.int, pApp uintptr, xFunc unsafe.Pointer, xStep unsafe.Pointer, xFinal unsafe.Pointer) C.int {
-	return C._sqlite3_create_function(db, zFunctionName, nArg, eTextRep, C.uintptr_t(pApp), (*[0]byte)(xFunc), (*[0]byte)(xStep), (*[0]byte)(xFinal))
+func sqlite3CreateFunction(db *C.sqlite3, zFunctionName *C.char, nArg C.int, eTextRep C.int, pApp unsafe.Pointer, xFunc unsafe.Pointer, xStep unsafe.Pointer, xFinal unsafe.Pointer) C.int {
+	return C._sqlite3_create_function(db, zFunctionName, nArg, eTextRep, C.uintptr_t(uintptr(pApp)), (*[0]byte)(xFunc), (*[0]byte)(xStep), (*[0]byte)(xFinal))
 }
 
 // RegisterAggregator makes a Go type available as a SQLite aggregation function.
@@ -1010,13 +1010,6 @@ func (c *SQLiteConn) begin(ctx context.Context) (driver.Tx, error) {
 //     Warning: misuse of this pragma can easily result in a corrupt database file.
 //
 //
-// go-sqlcipher adds the following query parameters to those used by SQLite:
-//
-//   _pragma_key=XXX
-//     Specify PRAGMA key.
-//
-//   _pragma_cipher_page_size=XXX
-//     Set the PRAGMA cipher_page_size to adjust the page size.
 func (d *SQLiteDriver) Open(dsn string) (driver.Conn, error) {
 	if C.sqlite3_threadsafe() == 0 {
 		return nil, errors.New("sqlite library was not compiled for thread-safe operation")
@@ -1048,6 +1041,7 @@ func (d *SQLiteDriver) Open(dsn string) (driver.Conn, error) {
 	secureDelete := "DEFAULT"
 	synchronousMode := "NORMAL"
 	writableSchema := -1
+	vfsName := ""
 
 	// SQLCipher PRAGMA's
 	pragmaKey := ""
@@ -1375,6 +1369,10 @@ func (d *SQLiteDriver) Open(dsn string) (driver.Conn, error) {
 			}
 		}
 
+		if val := params.Get("vfs"); val != "" {
+			vfsName = val
+		}
+
 		// _pragma_key
 		if val := params.Get("_pragma_key"); val != "" {
 			pragmaKey = val
@@ -1397,9 +1395,14 @@ func (d *SQLiteDriver) Open(dsn string) (driver.Conn, error) {
 	var db *C.sqlite3
 	name := C.CString(dsn)
 	defer C.free(unsafe.Pointer(name))
+	var vfs *C.char
+	if vfsName != "" {
+		vfs = C.CString(vfsName)
+		defer C.free(unsafe.Pointer(vfs))
+	}
 	rv := C._sqlite3_open_v2(name, &db,
 		mutex|C.SQLITE_OPEN_READWRITE|C.SQLITE_OPEN_CREATE,
-		nil)
+		vfs)
 	if rv != 0 {
 		// Save off the error _before_ closing the database.
 		// This is safe even if db is nil.
@@ -1962,6 +1965,14 @@ func (s *SQLiteStmt) Exec(args []driver.Value) (driver.Result, error) {
 	return s.exec(context.Background(), list)
 }
 
+func isInterruptErr(err error) bool {
+	sqliteErr, ok := err.(Error)
+	if ok {
+		return sqliteErr.Code == ErrInterrupt
+	}
+	return false
+}
+
 // exec executes a query that doesn't return rows. Attempts to honor context timeout.
 func (s *SQLiteStmt) exec(ctx context.Context, args []namedValue) (driver.Result, error) {
 	if ctx.Done() == nil {
@@ -1977,19 +1988,22 @@ func (s *SQLiteStmt) exec(ctx context.Context, args []namedValue) (driver.Result
 		r, err := s.execSync(args)
 		resultCh <- result{r, err}
 	}()
+	var rv result
 	select {
-	case rv := <-resultCh:
-		return rv.r, rv.err
+	case rv = <-resultCh:
 	case <-ctx.Done():
 		select {
-		case <-resultCh: // no need to interrupt
+		case rv = <-resultCh: // no need to interrupt, operation completed in db
 		default:
 			// this is still racy and can be no-op if executed between sqlite3_* calls in execSync.
 			C.sqlite3_interrupt(s.c.db)
-			<-resultCh // ensure goroutine completed
+			rv = <-resultCh // wait for goroutine completed
+			if isInterruptErr(rv.err) {
+				return nil, ctx.Err()
+			}
 		}
-		return nil, ctx.Err()
 	}
+	return rv.r, rv.err
 }
 
 func (s *SQLiteStmt) execSync(args []namedValue) (driver.Result, error) {
diff --git a/sqlite3_go113_test.go b/sqlite3_go113_test.go
new file mode 100644
index 0000000..6f74e6b
--- /dev/null
+++ b/sqlite3_go113_test.go
@@ -0,0 +1,78 @@
+// Copyright (C) 2019 Yasuhiro Matsumoto <mattn.jp@gmail.com>.
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file.
+
+// +build go1.13,cgo
+
+package sqlite3
+
+import (
+	"context"
+	"database/sql"
+	"database/sql/driver"
+	"os"
+	"testing"
+)
+
+func TestBeginTxCancel(t *testing.T) {
+	srcTempFilename := TempFilename(t)
+	defer os.Remove(srcTempFilename)
+
+	db, err := sql.Open("sqlite3", srcTempFilename)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	db.SetMaxOpenConns(10)
+	db.SetMaxIdleConns(5)
+
+	defer db.Close()
+	initDatabase(t, db, 100)
+
+	// create several go-routines to expose racy issue
+	for i := 0; i < 1000; i++ {
+		func() {
+			ctx, cancel := context.WithCancel(context.Background())
+			conn, err := db.Conn(ctx)
+			if err != nil {
+				t.Fatal(err)
+			}
+			defer func() {
+				if err := conn.Close(); err != nil {
+					t.Error(err)
+				}
+			}()
+
+			err = conn.Raw(func(driverConn interface{}) error {
+				d, ok := driverConn.(driver.ConnBeginTx)
+				if !ok {
+					t.Fatal("unexpected: wrong type")
+				}
+				// checks that conn.Raw can be used to get *SQLiteConn
+				if _, ok = driverConn.(*SQLiteConn); !ok {
+					t.Fatalf("conn.Raw() driverConn type=%T, expected *SQLiteConn", driverConn)
+				}
+
+				go cancel() // make it cancel concurrently with exec("BEGIN");
+				tx, err := d.BeginTx(ctx, driver.TxOptions{})
+				switch err {
+				case nil:
+					switch err := tx.Rollback(); err {
+					case nil, sql.ErrTxDone:
+					default:
+						return err
+					}
+				case context.Canceled:
+				default:
+					// must not fail with "cannot start a transaction within a transaction"
+					return err
+				}
+				return nil
+			})
+			if err != nil {
+				t.Fatal(err)
+			}
+		}()
+	}
+}
diff --git a/sqlite3_go18_test.go b/sqlite3_go18_test.go
index cfc89b0..8c8c451 100644
--- a/sqlite3_go18_test.go
+++ b/sqlite3_go18_test.go
@@ -136,6 +136,50 @@ func TestShortTimeout(t *testing.T) {
 	}
 }
 
+func TestExecContextCancel(t *testing.T) {
+	srcTempFilename := TempFilename(t)
+	defer os.Remove(srcTempFilename)
+
+	db, err := sql.Open("sqlite3", srcTempFilename)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	defer db.Close()
+
+	ts := time.Now()
+	initDatabase(t, db, 1000)
+	spent := time.Since(ts)
+	const minTestTime = 100 * time.Millisecond
+	if spent < minTestTime {
+		t.Skipf("test will be too racy (spent=%s < min=%s) as ExecContext below will be too fast.",
+			spent.String(), minTestTime.String(),
+		)
+	}
+
+	// expected to be extremely slow query
+	q := `
+INSERT INTO test_table (key1, key_id, key2, key3, key4, key5, key6, data)
+SELECT t1.key1 || t2.key1, t1.key_id || t2.key_id, t1.key2 || t2.key2, t1.key3 || t2.key3, t1.key4 || t2.key4, t1.key5 || t2.key5, t1.key6 || t2.key6, t1.data || t2.data
+FROM test_table t1 LEFT OUTER JOIN test_table t2`
+	// expect query above take ~ same time as setup above
+	// This is racy: the context must be valid so sql/db.ExecContext calls the sqlite3 driver.
+	// It starts the query, the context expires, then calls sqlite3_interrupt
+	ctx, cancel := context.WithTimeout(context.Background(), minTestTime/2)
+	defer cancel()
+	ts = time.Now()
+	r, err := db.ExecContext(ctx, q)
+	// racy check
+	if r != nil {
+		n, err := r.RowsAffected()
+		t.Logf("query should not have succeeded: rows=%d; err=%v; duration=%s",
+			n, err, time.Since(ts).String())
+	}
+	if err != context.DeadlineExceeded {
+		t.Fatal(err, ctx.Err())
+	}
+}
+
 func TestQueryRowContextCancel(t *testing.T) {
 	srcTempFilename := TempFilename(t)
 	defer os.Remove(srcTempFilename)
@@ -191,7 +235,7 @@ func TestQueryRowContextCancelParallel(t *testing.T) {
 	testCtx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	for i := 0; i < 50; i++ {
+	for i := 0; i < 10; i++ {
 		wg.Add(1)
 		go func() {
 			defer wg.Done()
diff --git a/sqlite3_libsqlite3.go b/sqlite3_libsqlite3.go
index bd6de0b..e428fe6 100644
--- a/sqlite3_libsqlite3.go
+++ b/sqlite3_libsqlite3.go
@@ -14,5 +14,6 @@ package sqlite3
 #cgo darwin CFLAGS: -I/usr/local/opt/sqlite/include
 #cgo openbsd LDFLAGS: -lsqlite3
 #cgo solaris LDFLAGS: -lsqlite3
+#cgo windows LDFLAGS: -lsqlite3
 */
 import "C"
diff --git a/sqlite3_load_extension.go b/sqlite3_load_extension.go
index e6c50f2..f241819 100644
--- a/sqlite3_load_extension.go
+++ b/sqlite3_load_extension.go
@@ -68,7 +68,7 @@ func (c *SQLiteConn) loadExtension(lib string, entry *string) error {
 
 	var centry *C.char
 	if entry != nil {
-		centry := C.CString(*entry)
+		centry = C.CString(*entry)
 		defer C.free(unsafe.Pointer(centry))
 	}
 
diff --git a/sqlite3_opt_vtable.go b/sqlite3_opt_vtable.go
index 50c9429..c0a6214 100644
--- a/sqlite3_opt_vtable.go
+++ b/sqlite3_opt_vtable.go
@@ -288,10 +288,13 @@ type InfoOrderBy struct {
 }
 
 func constraints(info *C.sqlite3_index_info) []InfoConstraint {
-	l := info.nConstraint
-	slice := (*[1 << 30]C.struct_sqlite3_index_constraint)(unsafe.Pointer(info.aConstraint))[:l:l]
+	slice := *(*[]C.struct_sqlite3_index_constraint)(unsafe.Pointer(&reflect.SliceHeader{
+		Data: uintptr(unsafe.Pointer(info.aConstraint)),
+		Len:  int(info.nConstraint),
+		Cap:  int(info.nConstraint),
+	}))
 
-	cst := make([]InfoConstraint, 0, l)
+	cst := make([]InfoConstraint, 0, len(slice))
 	for _, c := range slice {
 		var usable bool
 		if c.usable > 0 {
@@ -307,10 +310,13 @@ func constraints(info *C.sqlite3_index_info) []InfoConstraint {
 }
 
 func orderBys(info *C.sqlite3_index_info) []InfoOrderBy {
-	l := info.nOrderBy
-	slice := (*[1 << 30]C.struct_sqlite3_index_orderby)(unsafe.Pointer(info.aOrderBy))[:l:l]
+	slice := *(*[]C.struct_sqlite3_index_orderby)(unsafe.Pointer(&reflect.SliceHeader{
+		Data: uintptr(unsafe.Pointer(info.aOrderBy)),
+		Len:  int(info.nOrderBy),
+		Cap:  int(info.nOrderBy),
+	}))
 
-	ob := make([]InfoOrderBy, 0, l)
+	ob := make([]InfoOrderBy, 0, len(slice))
 	for _, c := range slice {
 		var desc bool
 		if c.desc > 0 {
@@ -347,7 +353,7 @@ func mPrintf(format, arg string) *C.char {
 
 //export goMInit
 func goMInit(db, pClientData unsafe.Pointer, argc C.int, argv **C.char, pzErr **C.char, isCreate C.int) C.uintptr_t {
-	m := lookupHandle(uintptr(pClientData)).(*sqliteModule)
+	m := lookupHandle(pClientData).(*sqliteModule)
 	if m.c.db != (*C.sqlite3)(db) {
 		*pzErr = mPrintf("%s", "Inconsistent db handles")
 		return 0
@@ -373,12 +379,12 @@ func goMInit(db, pClientData unsafe.Pointer, argc C.int, argv **C.char, pzErr **
 	}
 	vt := sqliteVTab{m, vTab}
 	*pzErr = nil
-	return C.uintptr_t(newHandle(m.c, &vt))
+	return C.uintptr_t(uintptr(newHandle(m.c, &vt)))
 }
 
 //export goVRelease
 func goVRelease(pVTab unsafe.Pointer, isDestroy C.int) *C.char {
-	vt := lookupHandle(uintptr(pVTab)).(*sqliteVTab)
+	vt := lookupHandle(pVTab).(*sqliteVTab)
 	var err error
 	if isDestroy == 1 {
 		err = vt.vTab.Destroy()
@@ -393,7 +399,7 @@ func goVRelease(pVTab unsafe.Pointer, isDestroy C.int) *C.char {
 
 //export goVOpen
 func goVOpen(pVTab unsafe.Pointer, pzErr **C.char) C.uintptr_t {
-	vt := lookupHandle(uintptr(pVTab)).(*sqliteVTab)
+	vt := lookupHandle(pVTab).(*sqliteVTab)
 	vTabCursor, err := vt.vTab.Open()
 	if err != nil {
 		*pzErr = mPrintf("%s", err.Error())
@@ -401,12 +407,12 @@ func goVOpen(pVTab unsafe.Pointer, pzErr **C.char) C.uintptr_t {
 	}
 	vtc := sqliteVTabCursor{vt, vTabCursor}
 	*pzErr = nil
-	return C.uintptr_t(newHandle(vt.module.c, &vtc))
+	return C.uintptr_t(uintptr(newHandle(vt.module.c, &vtc)))
 }
 
 //export goVBestIndex
 func goVBestIndex(pVTab unsafe.Pointer, icp unsafe.Pointer) *C.char {
-	vt := lookupHandle(uintptr(pVTab)).(*sqliteVTab)
+	vt := lookupHandle(pVTab).(*sqliteVTab)
 	info := (*C.sqlite3_index_info)(icp)
 	csts := constraints(info)
 	res, err := vt.vTab.BestIndex(csts, orderBys(info))
@@ -418,13 +424,17 @@ func goVBestIndex(pVTab unsafe.Pointer, icp unsafe.Pointer) *C.char {
 	}
 
 	// Get a pointer to constraint_usage struct so we can update in place.
-	l := info.nConstraint
-	s := (*[1 << 30]C.struct_sqlite3_index_constraint_usage)(unsafe.Pointer(info.aConstraintUsage))[:l:l]
+
+	slice := *(*[]C.struct_sqlite3_index_constraint_usage)(unsafe.Pointer(&reflect.SliceHeader{
+		Data: uintptr(unsafe.Pointer(info.aConstraintUsage)),
+		Len:  int(info.nConstraint),
+		Cap:  int(info.nConstraint),
+	}))
 	index := 1
-	for i := C.int(0); i < info.nConstraint; i++ {
+	for i := range slice {
 		if res.Used[i] {
-			s[i].argvIndex = C.int(index)
-			s[i].omit = C.uchar(1)
+			slice[i].argvIndex = C.int(index)
+			slice[i].omit = C.uchar(1)
 			index++
 		}
 	}
@@ -445,7 +455,7 @@ func goVBestIndex(pVTab unsafe.Pointer, icp unsafe.Pointer) *C.char {
 
 //export goVClose
 func goVClose(pCursor unsafe.Pointer) *C.char {
-	vtc := lookupHandle(uintptr(pCursor)).(*sqliteVTabCursor)
+	vtc := lookupHandle(pCursor).(*sqliteVTabCursor)
 	err := vtc.vTabCursor.Close()
 	if err != nil {
 		return mPrintf("%s", err.Error())
@@ -455,13 +465,13 @@ func goVClose(pCursor unsafe.Pointer) *C.char {
 
 //export goMDestroy
 func goMDestroy(pClientData unsafe.Pointer) {
-	m := lookupHandle(uintptr(pClientData)).(*sqliteModule)
+	m := lookupHandle(pClientData).(*sqliteModule)
 	m.module.DestroyModule()
 }
 
 //export goVFilter
 func goVFilter(pCursor unsafe.Pointer, idxNum C.int, idxName *C.char, argc C.int, argv **C.sqlite3_value) *C.char {
-	vtc := lookupHandle(uintptr(pCursor)).(*sqliteVTabCursor)
+	vtc := lookupHandle(pCursor).(*sqliteVTabCursor)
 	args := (*[(math.MaxInt32 - 1) / unsafe.Sizeof((*C.sqlite3_value)(nil))]*C.sqlite3_value)(unsafe.Pointer(argv))[:argc:argc]
 	vals := make([]interface{}, 0, argc)
 	for _, v := range args {
@@ -480,7 +490,7 @@ func goVFilter(pCursor unsafe.Pointer, idxNum C.int, idxName *C.char, argc C.int
 
 //export goVNext
 func goVNext(pCursor unsafe.Pointer) *C.char {
-	vtc := lookupHandle(uintptr(pCursor)).(*sqliteVTabCursor)
+	vtc := lookupHandle(pCursor).(*sqliteVTabCursor)
 	err := vtc.vTabCursor.Next()
 	if err != nil {
 		return mPrintf("%s", err.Error())
@@ -490,7 +500,7 @@ func goVNext(pCursor unsafe.Pointer) *C.char {
 
 //export goVEof
 func goVEof(pCursor unsafe.Pointer) C.int {
-	vtc := lookupHandle(uintptr(pCursor)).(*sqliteVTabCursor)
+	vtc := lookupHandle(pCursor).(*sqliteVTabCursor)
 	err := vtc.vTabCursor.EOF()
 	if err {
 		return 1
@@ -500,7 +510,7 @@ func goVEof(pCursor unsafe.Pointer) C.int {
 
 //export goVColumn
 func goVColumn(pCursor, cp unsafe.Pointer, col C.int) *C.char {
-	vtc := lookupHandle(uintptr(pCursor)).(*sqliteVTabCursor)
+	vtc := lookupHandle(pCursor).(*sqliteVTabCursor)
 	c := (*SQLiteContext)(cp)
 	err := vtc.vTabCursor.Column(c, int(col))
 	if err != nil {
@@ -511,7 +521,7 @@ func goVColumn(pCursor, cp unsafe.Pointer, col C.int) *C.char {
 
 //export goVRowid
 func goVRowid(pCursor unsafe.Pointer, pRowid *C.sqlite3_int64) *C.char {
-	vtc := lookupHandle(uintptr(pCursor)).(*sqliteVTabCursor)
+	vtc := lookupHandle(pCursor).(*sqliteVTabCursor)
 	rowid, err := vtc.vTabCursor.Rowid()
 	if err != nil {
 		return mPrintf("%s", err.Error())
@@ -522,7 +532,7 @@ func goVRowid(pCursor unsafe.Pointer, pRowid *C.sqlite3_int64) *C.char {
 
 //export goVUpdate
 func goVUpdate(pVTab unsafe.Pointer, argc C.int, argv **C.sqlite3_value, pRowid *C.sqlite3_int64) *C.char {
-	vt := lookupHandle(uintptr(pVTab)).(*sqliteVTab)
+	vt := lookupHandle(pVTab).(*sqliteVTab)
 
 	var tname string
 	if n, ok := vt.vTab.(interface {
@@ -642,7 +652,7 @@ func (c *SQLiteConn) CreateModule(moduleName string, module Module) error {
 	mname := C.CString(moduleName)
 	defer C.free(unsafe.Pointer(mname))
 	udm := sqliteModule{c, moduleName, module}
-	rv := C._sqlite3_create_module(c.db, mname, C.uintptr_t(newHandle(c, &udm)))
+	rv := C._sqlite3_create_module(c.db, mname, C.uintptr_t(uintptr(newHandle(c, &udm))))
 	if rv != C.SQLITE_OK {
 		return c.lastError()
 	}
diff --git a/sqlite3_test.go b/sqlite3_test.go
index d5b0cea..878ec49 100644
--- a/sqlite3_test.go
+++ b/sqlite3_test.go
@@ -19,6 +19,7 @@ import (
 	"os"
 	"reflect"
 	"regexp"
+	"runtime"
 	"strconv"
 	"strings"
 	"sync"
@@ -101,6 +102,43 @@ func TestOpen(t *testing.T) {
 	}
 }
 
+func TestOpenWithVFS(t *testing.T) {
+	filename := t.Name() + ".sqlite"
+
+	if err := os.Remove(filename); err != nil && !os.IsNotExist(err) {
+		t.Fatal(err)
+	}
+	defer os.Remove(filename)
+
+	db, err := sql.Open("sqlite3", fmt.Sprintf("file:%s?vfs=hello", filename))
+	if err != nil {
+		t.Fatal("Failed to open", err)
+	}
+	err = db.Ping()
+	if err == nil {
+		t.Fatal("Failed to open", err)
+	}
+	db.Close()
+
+	defer os.Remove(filename)
+
+	var vfs string
+	if runtime.GOOS == "windows" {
+		vfs = "win32-none"
+	} else {
+		vfs = "unix-none"
+	}
+	db, err = sql.Open("sqlite3", fmt.Sprintf("file:%s?vfs=%s", filename, vfs))
+	if err != nil {
+		t.Fatal("Failed to open", err)
+	}
+	err = db.Ping()
+	if err != nil {
+		t.Fatal("Failed to ping", err)
+	}
+	db.Close()
+}
+
 func TestOpenNoCreate(t *testing.T) {
 	filename := t.Name() + ".sqlite"
 
diff --git a/upgrade/upgrade.go b/upgrade/upgrade.go
index d800227..8801130 100644
--- a/upgrade/upgrade.go
+++ b/upgrade/upgrade.go
@@ -1,5 +1,5 @@
 // +build !cgo
-// +build upgrade
+// +build upgrade,ignore
 
 package main