diff --git a/spatial-math.cabal b/spatial-math.cabal
--- a/spatial-math.cabal
+++ b/spatial-math.cabal
@@ -1,5 +1,5 @@
 name:                spatial-math
-version:             0.3.0.0
+version:             0.3.1.0
 synopsis:            3d math including quaternions/euler angles/dcms and utility functions
 description:         This is a port of my 'mathlib' C library: `https://github.com/ghorn/mathlib`
 license:             BSD3
diff --git a/src/SpatialMathT.hs b/src/SpatialMathT.hs
--- a/src/SpatialMathT.hs
+++ b/src/SpatialMathT.hs
@@ -75,6 +75,7 @@
 newtype Rot f1 f2 r a =
   Rot { unRot :: r a }
   deriving ( Functor, Foldable, Traversable
+           , Applicative
            , Storable
            , Num, Fractional, Eq, Show, Ord
            , Generic1, Generic