diff --git a/include/armadillo_bits/arma_forward.hpp b/include/armadillo_bits/arma_forward.hpp
index 580f8360..778a329b 100644
--- a/include/armadillo_bits/arma_forward.hpp
+++ b/include/armadillo_bits/arma_forward.hpp
@@ -288,7 +288,6 @@ template<typename T1> struct diagmat_proxy;
 
 template<typename T1> struct plain_unwrap;
 template<typename T1> struct quasi_unwrap;
-template<typename T1> struct       unwrap_check_mixed;
 
 template<typename T1> struct unwrap_cube;
 template<typename T1> struct unwrap_spmat;