diff --git a/Crypto/PubKey/ECC/Types.hs b/Crypto/PubKey/ECC/Types.hs
index dbf4957..5f693e7 100644
--- a/Crypto/PubKey/ECC/Types.hs
+++ b/Crypto/PubKey/ECC/Types.hs
@@ -28,6 +28,7 @@ module Crypto.PubKey.ECC.Types
 
 import           Data.Data
 import           Crypto.Internal.Imports
+import           Crypto.Number.Basic (numBits)
 
 -- | Define either a binary curve or a prime curve.
 data Curve = CurveF2m CurveBinary -- ^ 𝔽(2^m)