diff --git a/vfs_files.go b/vfs_files.go
index 8b96c18..05891fa 100644
--- a/vfs_files.go
+++ b/vfs_files.go
@@ -44,25 +44,25 @@ func vfsGetOpenFileID(file *os.File) (uint32, error) {
 		}
 	}
 
-	of := vfsOpenFile{
+	of := &vfsOpenFile{
 		file: file,
 		info: fi,
 		nref: 1,
 
-		vfsLocker: &vfsDebugLocker{},
+		vfsLocker: &vfsNoopLocker{},
 	}
 
 	// Find an empty slot.
 	for id, ptr := range vfsOpenFiles {
 		if ptr == nil {
-			vfsOpenFiles[id] = &of
+			vfsOpenFiles[id] = of
 			return uint32(id), nil
 		}
 	}
 
 	// Add a new slot.
 	id := len(vfsOpenFiles)
-	vfsOpenFiles = append(vfsOpenFiles, &of)
+	vfsOpenFiles = append(vfsOpenFiles, of)
 	return uint32(id), nil
 }
 
@@ -99,12 +99,12 @@ func (p vfsFilePtr) ID() uint32 {
 	return id
 }
 
-func (p vfsFilePtr) Lock() uint32 {
+func (p vfsFilePtr) Lock() vfsLockState {
 	lk, ok := p.Memory().ReadUint32Le(p.ptr + 2*wordSize)
 	if !ok {
 		panic(rangeErr)
 	}
-	return lk
+	return vfsLockState(lk)
 }
 
 func (p vfsFilePtr) SetID(id uint32) vfsFilePtr {
@@ -114,8 +114,8 @@ func (p vfsFilePtr) SetID(id uint32) vfsFilePtr {
 	return p
 }
 
-func (p vfsFilePtr) SetLock(lock uint32) vfsFilePtr {
-	if ok := p.Memory().WriteUint32Le(p.ptr+2*wordSize, lock); !ok {
+func (p vfsFilePtr) SetLock(lock vfsLockState) vfsFilePtr {
+	if ok := p.Memory().WriteUint32Le(p.ptr+2*wordSize, uint32(lock)); !ok {
 		panic(rangeErr)
 	}
 	return p
diff --git a/vfs_lock.go b/vfs_lock.go
index b36a937..6954ae8 100644
--- a/vfs_lock.go
+++ b/vfs_lock.go
@@ -52,20 +52,22 @@ const (
 	_SHARED_SIZE   = 510
 )
 
+type vfsLockState uint32
+
 type vfsLocker interface {
-	LockerState() uint32
+	LockState() vfsLockState
 
 	LockShared() uint32    // UNLOCKED -> SHARED
 	LockReserved() uint32  // SHARED -> RESERVED
 	LockPending() uint32   // SHARED|RESERVED -> PENDING
 	LockExclusive() uint32 // PENDING -> EXCLUSIVE
 	DowngradeLock() uint32 // SHARED <- EXCLUSIVE|PENDING|RESERVED
-	ReleaseLock() uint32   // UNLOCKED <- EXCLUSIVE|PENDING|RESERVED|SHARED
+	Unlock() uint32        // UNLOCKED <- EXCLUSIVE|PENDING|RESERVED|SHARED
 
-	CheckReserved() (bool, uint32)
+	CheckReservedLock() (bool, uint32)
 }
 
-func vfsLock(ctx context.Context, mod api.Module, pFile, eLock uint32) uint32 {
+func vfsLock(ctx context.Context, mod api.Module, pFile uint32, eLock vfsLockState) uint32 {
 	if assert && (eLock == _NO_LOCK || eLock == _PENDING_LOCK) {
 		panic(assertErr + " [d4oxww]")
 	}
@@ -92,7 +94,7 @@ func vfsLock(ctx context.Context, mod api.Module, pFile, eLock uint32) uint32 {
 	vfsOpenFilesMtx.Lock()
 	defer vfsOpenFilesMtx.Unlock()
 	of := vfsOpenFiles[ptr.ID()]
-	fLock := of.LockerState()
+	fLock := of.LockState()
 
 	// If some other connection has a lock that precludes the requested lock, return BUSY.
 	if cLock != fLock && (eLock > _SHARED_LOCK || fLock >= _PENDING_LOCK) {
@@ -155,7 +157,7 @@ func vfsLock(ctx context.Context, mod api.Module, pFile, eLock uint32) uint32 {
 	}
 }
 
-func vfsUnlock(ctx context.Context, mod api.Module, pFile, eLock uint32) uint32 {
+func vfsUnlock(ctx context.Context, mod api.Module, pFile uint32, eLock vfsLockState) uint32 {
 	if assert && (eLock != _NO_LOCK && eLock != _SHARED_LOCK) {
 		panic(assertErr + " [7i4jw3]")
 	}
@@ -171,7 +173,7 @@ func vfsUnlock(ctx context.Context, mod api.Module, pFile, eLock uint32) uint32
 	vfsOpenFilesMtx.Lock()
 	defer vfsOpenFilesMtx.Unlock()
 	of := vfsOpenFiles[ptr.ID()]
-	fLock := of.LockerState()
+	fLock := of.LockState()
 
 	if assert && of.shared <= 0 {
 		panic(assertErr + " [2bhkwg]")
@@ -206,7 +208,7 @@ func vfsUnlock(ctx context.Context, mod api.Module, pFile, eLock uint32) uint32
 		return _OK
 
 	case of.shared == 1:
-		if rc := of.ReleaseLock(); rc != _OK {
+		if rc := of.Unlock(); rc != _OK {
 			return uint32(IOERR_UNLOCK)
 		}
 		ptr.SetLock(_NO_LOCK)
@@ -230,7 +232,7 @@ func vfsCheckReservedLock(ctx context.Context, mod api.Module, pFile, pResOut ui
 	defer vfsOpenFilesMtx.Unlock()
 	of := vfsOpenFiles[ptr.ID()]
 
-	locked, rc := of.CheckReserved()
+	locked, rc := of.CheckReservedLock()
 	if rc != _OK {
 		return uint32(IOERR_CHECKRESERVEDLOCK)
 	}
diff --git a/vfs_lock_debug.go b/vfs_lock_noop.go
similarity index 62%
rename from vfs_lock_debug.go
rename to vfs_lock_noop.go
index 4b1ba31..22f04e3 100644
--- a/vfs_lock_debug.go
+++ b/vfs_lock_noop.go
@@ -2,17 +2,17 @@ package sqlite3
 
 const assert = true
 
-type vfsDebugLocker struct {
-	state uint32
+type vfsNoopLocker struct {
+	state vfsLockState
 }
 
-var _ vfsLocker = &vfsDebugLocker{}
+var _ vfsLocker = &vfsNoopLocker{}
 
-func (l *vfsDebugLocker) LockerState() uint32 {
+func (l *vfsNoopLocker) LockState() vfsLockState {
 	return l.state
 }
 
-func (l *vfsDebugLocker) LockShared() uint32 {
+func (l *vfsNoopLocker) LockShared() uint32 {
 	if assert && !(l.state == _NO_LOCK) {
 		panic(assertErr + " [wz9dcw]")
 	}
@@ -20,7 +20,7 @@ func (l *vfsDebugLocker) LockShared() uint32 {
 	return _OK
 }
 
-func (l *vfsDebugLocker) LockReserved() uint32 {
+func (l *vfsNoopLocker) LockReserved() uint32 {
 	if assert && !(l.state == _SHARED_LOCK) {
 		panic(assertErr + " [m9hcil]")
 	}
@@ -28,7 +28,7 @@ func (l *vfsDebugLocker) LockReserved() uint32 {
 	return _OK
 }
 
-func (l *vfsDebugLocker) LockPending() uint32 {
+func (l *vfsNoopLocker) LockPending() uint32 {
 	if assert && !(l.state == _SHARED_LOCK || l.state == _RESERVED_LOCK) {
 		panic(assertErr + " [wx8nk2]")
 	}
@@ -36,7 +36,7 @@ func (l *vfsDebugLocker) LockPending() uint32 {
 	return _OK
 }
 
-func (l *vfsDebugLocker) LockExclusive() uint32 {
+func (l *vfsNoopLocker) LockExclusive() uint32 {
 	if assert && !(l.state == _PENDING_LOCK) {
 		panic(assertErr + " [84nbax]")
 	}
@@ -44,7 +44,7 @@ func (l *vfsDebugLocker) LockExclusive() uint32 {
 	return _OK
 }
 
-func (l *vfsDebugLocker) DowngradeLock() uint32 {
+func (l *vfsNoopLocker) DowngradeLock() uint32 {
 	if assert && !(l.state > _SHARED_LOCK) {
 		panic(assertErr + " [je31i3]")
 	}
@@ -52,7 +52,7 @@ func (l *vfsDebugLocker) DowngradeLock() uint32 {
 	return _OK
 }
 
-func (l *vfsDebugLocker) ReleaseLock() uint32 {
+func (l *vfsNoopLocker) Unlock() uint32 {
 	if assert && !(l.state > _NO_LOCK) {
 		panic(assertErr + " [m6e9w5]")
 	}
@@ -60,8 +60,8 @@ func (l *vfsDebugLocker) ReleaseLock() uint32 {
 	return _OK
 }
 
-func (l *vfsDebugLocker) CheckReserved() (bool, uint32) {
-	if l.state > _SHARED_LOCK {
+func (l *vfsNoopLocker) CheckReservedLock() (bool, uint32) {
+	if l.state >= _RESERVED_LOCK {
 		return true, _OK
 	}
 	return false, _OK