diff --git a/tests/modules/programs/thunderbird/default.nix b/tests/modules/programs/thunderbird/default.nix
index a17755e1..0fddeec1 100644
--- a/tests/modules/programs/thunderbird/default.nix
+++ b/tests/modules/programs/thunderbird/default.nix
@@ -1,4 +1,5 @@
 {
   thunderbird = ./thunderbird.nix;
   thunderbird-with-firefox = ./thunderbird-with-firefox.nix;
+  thunderbird-native-messaging-host = ./thunderbird-native-messaging-host.nix;
 }
diff --git a/tests/modules/programs/thunderbird/thunderbird-native-messaging-host.nix b/tests/modules/programs/thunderbird/thunderbird-native-messaging-host.nix
new file mode 100644
index 00000000..57bef0f1
--- /dev/null
+++ b/tests/modules/programs/thunderbird/thunderbird-native-messaging-host.nix
@@ -0,0 +1,25 @@
+# Confirm that both Firefox and Thunderbird can be configured at the same time.
+{ lib, realPkgs, ... }:
+lib.recursiveUpdate (import ./thunderbird.nix { inherit lib realPkgs; }) {
+  programs.thunderbird = {
+    nativeMessagingHosts = with realPkgs;
+      [
+        # NOTE: this is not a real Thunderbird native host module but Firefox; no
+        # native hosts are currently packaged for nixpkgs or elsewhere, so we
+        # have to improvise. Packaging wise, Firefox and Thunderbird native hosts
+        # are identical though. The test doesn't care if the host was meant for
+        # either as long as the right paths are present in the package.
+        browserpass
+      ];
+  };
+
+  nmt.script = let
+    isDarwin = realPkgs.stdenv.hostPlatform.isDarwin;
+    nativeHostsDir = if isDarwin then
+      "Library/Mozilla/NativeMessagingHosts"
+    else
+      ".mozilla/native-messaging-hosts";
+  in ''
+    assertFileExists home-files/${nativeHostsDir}/com.github.browserpass.native.json
+  '';
+}
diff --git a/tests/modules/programs/thunderbird/thunderbird.nix b/tests/modules/programs/thunderbird/thunderbird.nix
index a5bb3148..75e83e67 100644
--- a/tests/modules/programs/thunderbird/thunderbird.nix
+++ b/tests/modules/programs/thunderbird/thunderbird.nix
@@ -66,16 +66,6 @@
       };
     };
 
-    nativeMessagingHosts = with realPkgs;
-      [
-        # NOTE: this is not a real Thunderbird native host module but Firefox; no
-        # native hosts are currently packaged for nixpkgs or elsewhere, so we
-        # have to improvise. Packaging wise, Firefox and Thunderbird native hosts
-        # are identical though. The test doesn't care if the host was meant for
-        # either as long as the right paths are present in the package.
-        browserpass
-      ];
-
     settings = {
       "general.useragent.override" = "";
       "privacy.donottrackheader.enabled" = true;
@@ -86,10 +76,6 @@
     isDarwin = realPkgs.stdenv.hostPlatform.isDarwin;
     configDir = if isDarwin then "Library/Thunderbird" else ".thunderbird";
     profilesDir = if isDarwin then "${configDir}/Profiles" else "${configDir}";
-    nativeHostsDir = if isDarwin then
-      "Library/Mozilla/NativeMessagingHosts"
-    else
-      ".mozilla/native-messaging-hosts";
     platform = if isDarwin then "darwin" else "linux";
   in ''
     assertFileExists home-files/${configDir}/profiles.ini
@@ -111,7 +97,5 @@
     assertFileExists home-files/${profilesDir}/first/chrome/userContent.css
     assertFileContent home-files/${profilesDir}/first/chrome/userContent.css \
       <(echo "* { color: red !important; }")
-
-    assertFileExists home-files/${nativeHostsDir}/com.github.browserpass.native.json
   '';
 }