diff --git a/NEWS b/NEWS
index ef7758ae..92661103 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,6 @@
+1.8.8.dev0
+ * #818: Allow the "--repository" flag to match across multiple configuration files.
+
 1.8.7
  * #736: Store included configuration files within each backup archive in support of the "config
    bootstrap" action. Previously, only top-level configuration files were stored.
diff --git a/borgmatic/config/validate.py b/borgmatic/config/validate.py
index 3ac205e8..bf9869be 100644
--- a/borgmatic/config/validate.py
+++ b/borgmatic/config/validate.py
@@ -167,11 +167,10 @@ def repositories_match(first, second):
 def guard_configuration_contains_repository(repository, configurations):
     '''
     Given a repository path and a dict mapping from config filename to corresponding parsed config
-    dict, ensure that the repository is declared exactly once in all of the configurations. If no
+    dict, ensure that the repository is declared at least once in all of the configurations. If no
     repository is given, skip this check.
 
-    Raise ValueError if the repository is not found in a configuration, or is declared multiple
-    times.
+    Raise ValueError if the repository is not found in any configurations.
     '''
     if not repository:
         return
@@ -186,9 +185,7 @@ def guard_configuration_contains_repository(repository, configurations):
     )
 
     if count == 0:
-        raise ValueError(f'Repository {repository} not found in configuration files')
-    if count > 1:
-        raise ValueError(f'Repository {repository} found in multiple configuration files')
+        raise ValueError(f'Repository "{repository}" not found in configuration files')
 
 
 def guard_single_repository_selected(repository, configurations):
diff --git a/setup.py b/setup.py
index b7d5b290..dd98bc5f 100644
--- a/setup.py
+++ b/setup.py
@@ -1,6 +1,6 @@
 from setuptools import find_packages, setup
 
-VERSION = '1.8.7'
+VERSION = '1.8.8.dev0'
 
 
 setup(
diff --git a/tests/unit/config/test_validate.py b/tests/unit/config/test_validate.py
index 182cbd17..93305158 100644
--- a/tests/unit/config/test_validate.py
+++ b/tests/unit/config/test_validate.py
@@ -184,21 +184,6 @@ def test_guard_configuration_contains_repository_errors_when_repository_missing_
         )
 
 
-def test_guard_configuration_contains_repository_errors_when_repository_matches_config_twice():
-    flexmock(module).should_receive('repositories_match').replace_with(
-        lambda first, second: first == second
-    )
-
-    with pytest.raises(ValueError):
-        module.guard_configuration_contains_repository(
-            repository='repo',
-            configurations={
-                'config.yaml': {'repositories': ['repo', 'repo2']},
-                'other.yaml': {'repositories': ['repo']},
-            },
-        )
-
-
 def test_guard_single_repository_selected_raises_when_multiple_repositories_configured_and_none_selected():
     with pytest.raises(ValueError):
         module.guard_single_repository_selected(