diff --git a/libraries/base/GHC/IO/Handle/Lock/Windows.hsc b/libraries/base/GHC/IO/Handle/Lock/Windows.hsc
index 45c060f901ffca37dd0de31259ebba81fa8fa8fc..1118e523ecd23ecf8edb274aec256fc7949060b6 100644
--- a/libraries/base/GHC/IO/Handle/Lock/Windows.hsc
+++ b/libraries/base/GHC/IO/Handle/Lock/Windows.hsc
@@ -29,8 +29,11 @@ import Foreign.C.Error
 import Foreign.C.Types
 import Foreign.Marshal.Alloc
 import Foreign.Marshal.Utils
+import GHC.Base
 import GHC.IO.FD
 import GHC.IO.Handle.FD
+import GHC.IO.Handle.Types (Handle)
+import GHC.IO.Handle.Lock.Common (LockMode(..))
 import GHC.Ptr
 import GHC.Windows