diff --git a/matrix/Dcm.hpp b/matrix/Dcm.hpp
index 834daf0845..3f0d969402 100644
--- a/matrix/Dcm.hpp
+++ b/matrix/Dcm.hpp
@@ -80,23 +80,29 @@ public:
     Dcm(const Quaternion<Type> &q)
     {
         Dcm &dcm = *this;
-        Type a = q(0);
-        Type b = q(1);
-        Type c = q(2);
-        Type d = q(3);
-        Type aSq = a * a;
-        Type bSq = b * b;
-        Type cSq = c * c;
-        Type dSq = d * d;
-        dcm(0, 0) = aSq + bSq - cSq - dSq;
-        dcm(0, 1) = 2 * (b * c - a * d);
-        dcm(0, 2) = 2 * (a * c + b * d);
-        dcm(1, 0) = 2 * (b * c + a * d);
-        dcm(1, 1) = aSq - bSq + cSq - dSq;
-        dcm(1, 2) = 2 * (c * d - a * b);
-        dcm(2, 0) = 2 * (b * d - a * c);
-        dcm(2, 1) = 2 * (a * b + c * d);
-        dcm(2, 2) = aSq - bSq - cSq + dSq;
+        const Type a = q(0);
+        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;
+        const Type bb = b * b;
+        const Type bc = b * c;
+        const Type bd = b * d;
+        const Type cc = c * c;
+        const Type cd = c * d;
+        const Type dd = d * d;
+        dcm(0, 0) = aa + bb - cc - dd;
+        dcm(0, 1) = 2 * (bc - ad);
+        dcm(0, 2) = 2 * (ac + bd);
+        dcm(1, 0) = 2 * (bc + ad);
+        dcm(1, 1) = aa - bb + cc - dd;
+        dcm(1, 2) = 2 * (cd - ab);
+        dcm(2, 0) = 2 * (bd - ac);
+        dcm(2, 1) = 2 * (ab + cd);
+        dcm(2, 2) = aa - bb - cc + dd;
     }
 
     /**