diff --git a/gnu/packages/mpi.scm b/gnu/packages/mpi.scm
index 517f91241778057b0fb1b1fad680dbb3b08f48f5..98b21219f5d11603f62aebdd0eb2050d26ab9700 100644
--- a/gnu/packages/mpi.scm
+++ b/gnu/packages/mpi.scm
@@ -131,6 +131,7 @@ (define-public openmpi
     (native-inputs
      `(("pkg-config" ,pkg-config)
        ("perl" ,perl)))
+    (outputs '("out" "debug"))
     (arguments
      `(#:configure-flags `("--enable-mpi-ext=affinity" ;cr doesn't work
                            "--enable-memchecker"