diff --git a/nixos/modules/tests/private-storage.nix b/nixos/modules/tests/private-storage.nix
index 2542802eccf829748d5ae10043e3e87d5ed133fe..4b01cdffa659cad057173e9bb866f64881df4a09 100644
--- a/nixos/modules/tests/private-storage.nix
+++ b/nixos/modules/tests/private-storage.nix
@@ -202,7 +202,6 @@ import <nixpkgs/nixos/tests/make-test.nix> {
       eval {
       ${runOnNode "introducer" [ run-introducer "/tmp/node.pem" (toString introducerPort) introducerFURL ]}
       } or do {
-        my $error = $@ || 'Unknown failure';
         my ($code, $log) = $introducer->execute('cat /tmp/stdout /tmp/stderr');
         $introducer->log($log);
         die $@;
@@ -246,7 +245,6 @@ import <nixpkgs/nixos/tests/make-test.nix> {
       eval {
         ${runOnNode "client" [ get-passes "http://127.0.0.1:3456" issuerURL voucher ]}
       } or do {
-        my $error = $@ || 'Unknown failure';
         my ($code, $log) = $client->execute('cat /tmp/stdout /tmp/stderr');
         $client->log($log);
 
@@ -261,28 +259,32 @@ import <nixpkgs/nixos/tests/make-test.nix> {
       eval {
         ${runOnNode "client" [ exercise-storage "/tmp/client" ]}
       } or do {
-        my $error = $@ || 'Unknown failure';
         my ($code, $log) = $client->execute('cat /tmp/stdout /tmp/stderr');
         $client->log($log);
         die $@;
       };
 
-      # It should be possible to restart the storage service.  Do so and
-      # ensure the client can still access it afterwards.
+      # It should be possible to restart the storage service without the
+      # storage node fURL changing.
       eval {
+        my $furlfile = '/var/db/tahoe-lafs/storage/private/storage-plugin.privatestorageio-zkapauthz-v1.furl';
+        my $before = $storage->execute('cat ' . $furlfile);
         ${runOnNode "storage" [ "systemctl" "restart" "tahoe.storage" ]}
+        my $after = $storage->execute('cat ' . $furlfile);
+        if ($before != $after) {
+          die 'fURL changes after storage node restart';
+        }
+        1;
       } or do {
-        my $error = $@ || 'Unknown failure';
         my ($code, $log) = $storage->execute('cat /tmp/stdout /tmp/stderr');
         $storage->log($log);
         die $@;
       };
 
-      # Same as above.
+      # The client should actually still work, too.
       eval {
         ${runOnNode "client" [ exercise-storage "/tmp/client" ]}
       } or do {
-        my $error = $@ || 'Unknown failure';
         my ($code, $log) = $client->execute('cat /tmp/stdout /tmp/stderr');
         $client->log($log);
         die $@;