diff --git a/cluster/kube/k0.libsonnet b/cluster/kube/k0.libsonnet
index 57f3269..756b00f 100644
--- a/cluster/kube/k0.libsonnet
+++ b/cluster/kube/k0.libsonnet
@@ -446,6 +446,11 @@
                         { namespace: "q3k", dns: "*.q3k.org" },
                         { namespace: "personal-q3k", dns: "*.q3k.org" },
                     ],
+
+                    anything_goes_namespace: [
+                        // sourcegraph ingress wants a config snippet to set a header.
+                        "devtools-prod",
+                    ],
                 },
             },
         },