diff --git a/tensorflow-ops/src/TensorFlow/Minimize.hs b/tensorflow-ops/src/TensorFlow/Minimize.hs
index 0062d54..f068be1 100644
--- a/tensorflow-ops/src/TensorFlow/Minimize.hs
+++ b/tensorflow-ops/src/TensorFlow/Minimize.hs
@@ -12,6 +12,8 @@
 -- See the License for the specific language governing permissions and
 -- limitations under the License.
 
+{-# LANGUAGE ConstraintKinds #-}
+{-# LANGUAGE DataKinds #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE RankNTypes #-}
@@ -22,11 +24,15 @@ module TensorFlow.Minimize
     ( Minimizer
     , minimizeWith
     , gradientDescent
+    , OneOfAdamDataTypes
     , AdamConfig(..)
     , adam
     , adam'
     ) where
 
+import Data.Complex
+import Data.Int
+import Data.Word
 import Control.Monad (zipWithM)
 import Data.Default (Default(..))
 import Data.List (zipWith4)
@@ -67,14 +73,19 @@ gradientDescent learningRate params grads = TF.withNameScope "gradientDescent" $
 
 -- TODO: Support more than Float in adam.
 
-data AdamConfig = AdamConfig
-    { adamLearningRate :: Float
-    , adamBeta1        :: Float
-    , adamBeta2        :: Float
-    , adamEpsilon      :: Float
+data AdamConfig t = AdamConfig
+    { adamLearningRate :: t
+    , adamBeta1        :: t
+    , adamBeta2        :: t
+    , adamEpsilon      :: t
     }
 
-instance Default AdamConfig where
+type OneOfAdamDataTypes t =
+        TF.OneOf '[ Complex Double, Complex Float
+                  , Int16, Int32, Int64, Int8, Word16, Word32, Word64, Word8
+                  , Double, Float] t
+
+instance Fractional t => Default (AdamConfig t) where
   -- Recommended defaults from the adam paper.
   def = AdamConfig 0.001 0.9 0.999 1e-8
 
@@ -83,10 +94,10 @@ instance Default AdamConfig where
 -- See https://arxiv.org/abs/1412.6980.
 --
 -- NOTE: Currently requires all 'TF.Variable's to have an 'TF.initializedValue'.
-adam :: Minimizer Float
+adam :: (OneOfAdamDataTypes t, Fractional t) => Minimizer t
 adam = adam' def
 
-adam' :: AdamConfig -> Minimizer Float
+adam' :: OneOfAdamDataTypes t => AdamConfig t -> Minimizer t
 adam' config params grads = TF.withNameScope "adam" $ do
     let lr = TF.scalar (adamLearningRate config)
         beta1 = TF.scalar (adamBeta1 config)