diff --git a/installer/assets/ingress/default-backend-configmap.yaml b/installer/assets/ingress/default-backend-configmap.yaml
index e458acd333..d7272a5233 100644
--- a/installer/assets/ingress/default-backend-configmap.yaml
+++ b/installer/assets/ingress/default-backend-configmap.yaml
@@ -4,3 +4,4 @@ metadata:
   name: tectonic-custom-error
 data:
   custom-http-errors: "400,401,403,404,500,503,504"
+  use-http2: "false"
diff --git a/modules/tectonic/resources/manifests/ingress/default-backend/configmap.yaml b/modules/tectonic/resources/manifests/ingress/default-backend/configmap.yaml
index bfb19b945d..814f5f1a6e 100644
--- a/modules/tectonic/resources/manifests/ingress/default-backend/configmap.yaml
+++ b/modules/tectonic/resources/manifests/ingress/default-backend/configmap.yaml
@@ -6,3 +6,4 @@ metadata:
 data:
   custom-http-errors: "400,401,403,404,500,503,504"
   server-name-hash-bucket-size: "1024"
+  use-http2: "false"