diff --git a/osu.Game.Tests/Visual/UserInterface/TestSceneBeatmapListingSearchControl.cs b/osu.Game.Tests/Visual/UserInterface/TestSceneBeatmapListingSearchControl.cs
index ff8162293b..e07aa71b1f 100644
--- a/osu.Game.Tests/Visual/UserInterface/TestSceneBeatmapListingSearchControl.cs
+++ b/osu.Game.Tests/Visual/UserInterface/TestSceneBeatmapListingSearchControl.cs
@@ -61,8 +61,8 @@ namespace osu.Game.Tests.Visual.UserInterface
             control.Category.BindValueChanged(c => category.Text = $"Category: {c.NewValue}", true);
             control.Genre.BindValueChanged(g => genre.Text = $"Genre: {g.NewValue}", true);
             control.Language.BindValueChanged(l => language.Text = $"Language: {l.NewValue}", true);
-            control.Extra.BindValueChanged(e => extra.Text = $"Extra: {(e.NewValue == null ? "" : string.Join(".", e.NewValue.Select(i => i.ToString().ToLowerInvariant())))}", true);
-            control.Ranks.BindValueChanged(r => ranks.Text = $"Ranks: {(r.NewValue == null ? "" : string.Join(".", r.NewValue.Select(i => i.ToString())))}", true);
+            control.Extra.BindValueChanged(e => extra.Text = $"Extra: {(e.NewValue == null ? "" : string.Join('.', e.NewValue.Select(i => i.ToString().ToLowerInvariant())))}", true);
+            control.Ranks.BindValueChanged(r => ranks.Text = $"Ranks: {(r.NewValue == null ? "" : string.Join('.', r.NewValue.Select(i => i.ToString())))}", true);
             control.Played.BindValueChanged(p => played.Text = $"Played: {p.NewValue}", true);
         }
 
diff --git a/osu.Game/Online/API/Requests/SearchBeatmapSetsRequest.cs b/osu.Game/Online/API/Requests/SearchBeatmapSetsRequest.cs
index f819a5778f..248096d8b3 100644
--- a/osu.Game/Online/API/Requests/SearchBeatmapSetsRequest.cs
+++ b/osu.Game/Online/API/Requests/SearchBeatmapSetsRequest.cs
@@ -81,10 +81,10 @@ namespace osu.Game.Online.API.Requests
             req.AddParameter("sort", $"{SortCriteria.ToString().ToLowerInvariant()}_{directionString}");
 
             if (Extra != null && Extra.Any())
-                req.AddParameter("e", string.Join(".", Extra.Select(e => e.ToString().ToLowerInvariant())));
+                req.AddParameter("e", string.Join('.', Extra.Select(e => e.ToString().ToLowerInvariant())));
 
             if (Ranks != null && Ranks.Any())
-                req.AddParameter("r", string.Join(".", Ranks.Select(r => r.ToString())));
+                req.AddParameter("r", string.Join('.', Ranks.Select(r => r.ToString())));
 
             if (Played != SearchPlayed.Any)
                 req.AddParameter("played", Played.ToString().ToLowerInvariant());