diff --git a/shell_integration/MacOSX/NextcloudIntegration/FinderSyncExt/FinderSync.m b/shell_integration/MacOSX/NextcloudIntegration/FinderSyncExt/FinderSync.m
index 5986da0790910..9d2c3a015c880 100644
--- a/shell_integration/MacOSX/NextcloudIntegration/FinderSyncExt/FinderSync.m
+++ b/shell_integration/MacOSX/NextcloudIntegration/FinderSyncExt/FinderSync.m
@@ -207,7 +207,7 @@ - (void)reFetchFileNameCacheForPath:(NSString*)path
 
 - (void)registerPath:(NSString*)path
 {
-	assert(_registeredDirectories);
+	NSAssert(_registeredDirectories, @"Registered directories should be a valid set!");
 	[_registeredDirectories addObject:[NSURL fileURLWithPath:path]];
 	[FIFinderSyncController defaultController].directoryURLs = _registeredDirectories;
 }