objects should be morphisms

Thanks to Alex
http://stacks.math.columbia.edu/tag/03T3#comment-2167

etale-cohomology.tex

@@ -13682,7 +13682,8 @@ \section{Derived categories}
 To set up notation, let $\mathcal{A}$ be an abelian category. Let
 $\text{Comp}(\mathcal{A})$ be the abelian category of complexes in
 $\mathcal{A}$. Let $K(\mathcal{A})$ be the category of complexes up to
-homotopy, with objects equal to complexes in $\mathcal{A}$ and objects equal to
+homotopy, with objects equal to complexes in $\mathcal{A}$ and morphisms
+equal to
 homotopy classes of morphisms of complexes. This is not an abelian category.
 Loosely speaking, $D(A)$ is defined to be the category obtained by inverting
 all quasi-isomorphisms in $\text{Comp}(\mathcal{A})$ or, equivalently, in