diff --git a/src/NzbDrone.Core/ImportLists/ImportListSyncService.cs b/src/NzbDrone.Core/ImportLists/ImportListSyncService.cs
index 60c118a6a0..b96e07a0fb 100644
--- a/src/NzbDrone.Core/ImportLists/ImportListSyncService.cs
+++ b/src/NzbDrone.Core/ImportLists/ImportListSyncService.cs
@@ -196,7 +196,9 @@ private void CleanLibrary()
 
             foreach (var movie in moviesInLibrary)
             {
-                var movieExists = listMovies.Any(c => c.TmdbId == movie.TmdbId || c.ImdbId == movie.ImdbId);
+                var movieExists = listMovies.Any(c =>
+                    c.TmdbId == movie.TmdbId ||
+                    (c.ImdbId.IsNotNullOrWhiteSpace() && movie.ImdbId.IsNotNullOrWhiteSpace() && c.ImdbId == movie.ImdbId));
 
                 if (!movieExists)
                 {