diff --git a/tests/properties/Tests.hs b/tests/properties/Tests.hs
index a0b7d35..8fcfd36 100644
--- a/tests/properties/Tests.hs
+++ b/tests/properties/Tests.hs
@@ -1,2 +1,2 @@
-{-# LANGUAGE ImpredicativeTypes, RankNTypes, TypeOperators, FlexibleContexts #-}
+{-# LANGUAGE ImpredicativeTypes, RankNTypes, TypeOperators, FlexibleContexts, ScopedTypeVariables #-}
 
@@ -44,4 +44,4 @@ args = stdArgs
 
-check_Int_sort = forM_ algos $ \(name,algo) ->
-  quickCheckWith args (label name . prop_fullsort algo)
+check_Int_sort = forM_ algos (\(name,algo :: Algo Int ()) ->
+  quickCheckWith args (label name . prop_fullsort algo))
  where
@@ -55,4 +55,4 @@ check_Int_sort = forM_ algos $ \(name,algo) ->
 
-check_Int_partialsort = forM_ algos $ \(name,algo) ->
-  quickCheckWith args (label name . prop_partialsort algo)
+check_Int_partialsort = forM_ algos (\(name,algo :: SizeAlgo Int ()) ->
+  quickCheckWith args (label name . prop_partialsort algo))
  where
@@ -63,4 +63,4 @@ check_Int_partialsort = forM_ algos $ \(name,algo) ->
 
-check_Int_select = forM_ algos $ \(name,algo) ->
-  quickCheckWith args (label name . prop_select algo)
+check_Int_select = forM_ algos (\(name,algo :: SizeAlgo Int ()) ->
+  quickCheckWith args (label name . prop_select algo))
  where
@@ -119,10 +119,10 @@ check_permutation = do
   qc $ label "introsort"    . prop_permutation (INT.sort :: Algo Int ())
-  qc $ label "intropartial" . prop_sized (const . prop_permutation)
+  qc $ label "intropartial" . prop_sized (\x -> const (prop_permutation x))
                                          (INT.partialSort :: SizeAlgo Int ())
-  qc $ label "introselect"  . prop_sized (const . prop_permutation)
+  qc $ label "introselect"  . prop_sized (\x -> const (prop_permutation x))
                                          (INT.select :: SizeAlgo Int ())
   qc $ label "heapsort"     . prop_permutation (H.sort :: Algo Int ())
-  qc $ label "heappartial"  . prop_sized (const . prop_permutation)
+  qc $ label "heappartial"  . prop_sized (\x -> const (prop_permutation x))
                                          (H.partialSort :: SizeAlgo Int ())
-  qc $ label "heapselect"   . prop_sized (const . prop_permutation)
+  qc $ label "heapselect"   . prop_sized (\x -> const (prop_permutation x))
                                          (H.select :: SizeAlgo Int ())