diff --git a/quaternion.cpp b/quaternion.cpp
index 99aa7aaf..2c0cd543 100644
--- a/quaternion.cpp
+++ b/quaternion.cpp
@@ -111,8 +111,8 @@ quaternion<S, T>::as_matrix (void) const
     const T yy = this->y * this->y, yz = this->y * this->z, zz = this->z * this->z;
 
     return { {
-        { 1 - 2 * (yy - zz),     2 * (xy - wz),     2 * (xz + wy), 0 },
-        {     2 * (xy + wz), 1 - 2 * (xx - zz),     2 * (yz - wx), 0 },
+        { 1 - 2 * (yy + zz),     2 * (xy - wz),     2 * (xz + wy), 0 },
+        {     2 * (xy + wz), 1 - 2 * (xx + zz),     2 * (yz - wx), 0 },
         {     2 * (xz - wy),     2 * (yz + wx), 1 - 2 * (xx + yy), 0 },
         {                 0,                 0,                 0, 1 }
     } };
diff --git a/test/quaternion.cpp b/test/quaternion.cpp
index 89132702..d82ade7a 100644
--- a/test/quaternion.cpp
+++ b/test/quaternion.cpp
@@ -68,9 +68,9 @@ main (void)
             float mag;
             util::vector3f axis;
         } ROTATIONS[] = {
-            { 0.f, { 1.f, 0.f, 0.f } },
+            { 1.f, { 1.f, 0.f, 0.f } },
             { 1.f, { 0.f, 1.f, 0.f } },
-            { 0.f, { 0.f, 0.f, 1.f } },
+            { 1.f, { 0.f, 0.f, 1.f } },
         };
 
         for (size_t i = 0; i < elems (ROTATIONS); ++i) {