diff --git a/nixos/tests/common/acme/server/generate-certs.nix b/nixos/tests/common/acme/server/generate-certs.nix
index 0cec83282707..a95c58a45964 100644
--- a/nixos/tests/common/acme/server/generate-certs.nix
+++ b/nixos/tests/common/acme/server/generate-certs.nix
@@ -4,11 +4,8 @@
   pkgs ? import <nixpkgs> { },
   minica ? pkgs.minica,
   mkDerivation ? pkgs.stdenv.mkDerivation,
+  domain ? (import ./snakeoil-certs.nix).domain,
 }:
-let
-  conf = import ./snakeoil-certs.nix;
-  domain = conf.domain;
-in
 mkDerivation {
   name = "test-certs";
   buildInputs = [
diff --git a/nixos/tests/redlib.nix b/nixos/tests/redlib.nix
index e03df475fe3d..9d7e7ec1632a 100644
--- a/nixos/tests/redlib.nix
+++ b/nixos/tests/redlib.nix
@@ -1,4 +1,8 @@
 { lib, pkgs, ... }:
+let
+  certs = import redlib/snakeoil-certs.nix;
+  redditDomain = certs.domain;
+in
 {
   name = "redlib";
   meta.maintainers = with lib.maintainers; [
@@ -7,6 +11,24 @@
   ];
 
   nodes.machine = {
+    # The test will hang if Redlib can't initialize its OAuth client, so we
+    # provide it with a mock endpoint.
+    networking.hosts."127.0.0.1" = [ redditDomain ];
+    security.pki.certificates = [
+      (builtins.readFile certs.ca.cert)
+    ];
+    services.nginx = {
+      enable = true;
+      virtualHosts.${redditDomain} = {
+        onlySSL = true;
+        sslCertificate = certs.${redditDomain}.cert;
+        sslCertificateKey = certs.${redditDomain}.key;
+        locations."/auth/v2/oauth/access-token/loid".extraConfig = ''
+          return 200 "{\"access_token\":\"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\",\"expires_in\":0}";
+        '';
+      };
+    };
+
     services.redlib = {
       package = pkgs.redlib;
       enable = true;
diff --git a/nixos/tests/redlib/ca.cert.pem b/nixos/tests/redlib/ca.cert.pem
new file mode 100644
index 000000000000..0e0496e1ac37
--- /dev/null
+++ b/nixos/tests/redlib/ca.cert.pem
@@ -0,0 +1,13 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
diff --git a/nixos/tests/redlib/ca.key.pem b/nixos/tests/redlib/ca.key.pem
new file mode 100644
index 000000000000..d085e8ba3f85
--- /dev/null
+++ b/nixos/tests/redlib/ca.key.pem
@@ -0,0 +1,6 @@
+-----BEGIN PRIVATE KEY-----
+MIG2AgEAMBAGByqGSM49AgEGBSuBBAAiBIGeMIGbAgEBBDBuuWbxl4uwwcIT0SvT
+jcQHDekytbQrLw4imrpfrAJmTdvyHcfEGiWuwscs36mq50WhZANiAASo81ED5tom
+fR47qFXpan+0cBKP7eoAhAAkJeT9w/h2axpVVQ/X+rDFu1QbKDqE7lJ2j3Ue7eb/
+6Q5Zrt9MSFPDcQz7eFr6kX0S2u5AHO9z6E60gUNUwZBDBenr0P/uTQ4=
+-----END PRIVATE KEY-----
diff --git a/nixos/tests/redlib/snakeoil-certs.nix b/nixos/tests/redlib/snakeoil-certs.nix
new file mode 100644
index 000000000000..6fd0badcca7d
--- /dev/null
+++ b/nixos/tests/redlib/snakeoil-certs.nix
@@ -0,0 +1,17 @@
+# To generate cert files:
+# cp $(nix-build ../common/acme/server/generate-certs.nix --arg domain '(import ./snakeoil-certs.nix).domain' --no-out-link)/* .
+
+let
+  domain = "www.reddit.com";
+in
+{
+  inherit domain;
+  ca = {
+    cert = ./ca.cert.pem;
+    key = ./ca.key.pem;
+  };
+  ${domain} = {
+    cert = ./${domain}.cert.pem;
+    key = ./${domain}.key.pem;
+  };
+}
diff --git a/nixos/tests/redlib/www.reddit.com.cert.pem b/nixos/tests/redlib/www.reddit.com.cert.pem
new file mode 100644
index 000000000000..fbd8636683f4
--- /dev/null
+++ b/nixos/tests/redlib/www.reddit.com.cert.pem
@@ -0,0 +1,13 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
diff --git a/nixos/tests/redlib/www.reddit.com.key.pem b/nixos/tests/redlib/www.reddit.com.key.pem
new file mode 100644
index 000000000000..d9f7056e6d68
--- /dev/null
+++ b/nixos/tests/redlib/www.reddit.com.key.pem
@@ -0,0 +1,6 @@
+-----BEGIN PRIVATE KEY-----
+MIG2AgEAMBAGByqGSM49AgEGBSuBBAAiBIGeMIGbAgEBBDB1r7aQH0yOtCYquZXn
+1jVqo9gD7kIZRa4TaeHNRRKcv9w9WswTfSJ/0QILIFP0K7WhZANiAAQpU1quYyW3
+g2ZjtwSFLNOhucqkjFhCN5rcSZOLpbnieelZ6axvoH6x2Znfcu4YqYtK8G/zHDv2
+o9gQQpDBcWp7dobpUVbfrSRxsr5LEYlEXPUslbFkFWauHzKTx5QTyu0=
+-----END PRIVATE KEY-----