diff --git a/src/Algebra/PartialOrd.hs b/src/Algebra/PartialOrd.hs
index 4c62535..ae6f95f 100644
--- a/src/Algebra/PartialOrd.hs
+++ b/src/Algebra/PartialOrd.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE Safe #-}
+{-# LANGUAGE DefaultSignatures #-}
 ----------------------------------------------------------------------------
 -- |
 -- Module      :  Algebra.PartialOrd
@@ -84,7 +85,9 @@ import           Data.Void         (Void)
 class Eq a => PartialOrd a where
     -- | The relation that induces the partial ordering
     leq :: a -> a -> Bool
-
+    {-# INLINE leq #-}
+    default leq :: Ord a => a -> a -> Bool
+    leq = (<=)
     -- | Whether two elements are ordered with respect to the relation. A
     -- default implementation is given by
     --