diff --git a/src/alire/alire-index_on_disk.adb b/src/alire/alire-index_on_disk.adb
index bea0c467d..1260a19e0 100644
--- a/src/alire/alire-index_on_disk.adb
+++ b/src/alire/alire-index_on_disk.adb
@@ -173,7 +173,7 @@ package body Alire.Index_On_Disk is
          Dir : constant Virtual_File := Create (+Path);
       begin
          if not Dir.Is_Directory then
-            Result := Outcome_Failure ("Not a readable directory");
+            Result := Outcome_Failure ("Not a readable directory: " & Path);
             return New_Invalid_Index;
          end if;
 
diff --git a/testsuite/tests/index/local-index-not-found/test.py b/testsuite/tests/index/local-index-not-found/test.py
index bc571e7ae..7f9ff901d 100644
--- a/testsuite/tests/index/local-index-not-found/test.py
+++ b/testsuite/tests/index/local-index-not-found/test.py
@@ -10,6 +10,11 @@
 from drivers.alr import prepare_indexes, run_alr
 from drivers.asserts import assert_match
 
+def comparator(param):
+    """If the test value (in d) is 'no-such-directory', the value tested for
+    is './no-such-directory'; if not, it's left as it is."""
+    if param == 'no-such-directory': return './no-such-directory'
+    return param
 
 for d in ('no-such-directory',
           'file://no-such-directory', ):
@@ -21,9 +26,9 @@
     path_excerpt = os.path.join('alr-config', 'indexes', 'bad_index',
                                 'index.toml')
     assert_match('ERROR: Cannot load metadata from .*{}:'
-                 ' Not a readable directory'
+                 ' Not a readable directory: {}'
                  '\n'
-                 .format(re.escape(path_excerpt)),
+                 .format(re.escape(path_excerpt), comparator(d)),
                  p.out)
 
 print('SUCCESS')