diff --git a/Eigen/src/Core/arch/CUDA/TypeCasting.h b/Eigen/src/Core/arch/CUDA/TypeCasting.h
index 38f7500ee..9b4fbe205 100644
--- a/Eigen/src/Core/arch/CUDA/TypeCasting.h
+++ b/Eigen/src/Core/arch/CUDA/TypeCasting.h
@@ -97,7 +97,7 @@ struct type_casting_traits<float, half> {
   };
 };
 
-template<> EIGEN_STRONG_INLINE half2 pcast<float4, half2>(const float4& a) {
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pcast<float4, half2>(const float4& a) {
   // Simply discard the second half of the input
   return __float22half2_rn(make_float2(a.x, a.y));
 }