diff --git a/src/lib/matrix/matrix/Dcm.hpp b/src/lib/matrix/matrix/Dcm.hpp
index 274728ceeb..b640572097 100644
--- a/src/lib/matrix/matrix/Dcm.hpp
+++ b/src/lib/matrix/matrix/Dcm.hpp
@@ -90,7 +90,6 @@ public:
 		const Type b = q(1);
 		const Type c = q(2);
 		const Type d = q(3);
-		const Type aa = a * a;
 		const Type ab = a * b;
 		const Type ac = a * c;
 		const Type ad = a * d;
@@ -100,15 +99,15 @@ public:
 		const Type cc = c * c;
 		const Type cd = c * d;
 		const Type dd = d * d;
-		dcm(0, 0) = aa + bb - cc - dd;
+		dcm(0, 0) = Type(1) - Type(2) * (cc + dd);
 		dcm(0, 1) = Type(2) * (bc - ad);
 		dcm(0, 2) = Type(2) * (ac + bd);
 		dcm(1, 0) = Type(2) * (bc + ad);
-		dcm(1, 1) = aa - bb + cc - dd;
+		dcm(1, 1) = Type(1) - Type(2) * (bb + dd);
 		dcm(1, 2) = Type(2) * (cd - ab);
 		dcm(2, 0) = Type(2) * (bd - ac);
 		dcm(2, 1) = Type(2) * (ab + cd);
-		dcm(2, 2) = aa - bb - cc + dd;
+		dcm(2, 2) = Type(1) - Type(2) * (bb + cc);
 	}
 
 	/**