diff --git a/osu.Game.Rulesets.Mania/Resources/Testing/Beatmaps/mania-samples.osu b/osu.Game.Rulesets.Mania/Resources/Testing/Beatmaps/mania-samples.osu
index 7c75b45e5f..ca9e5b0b85 100644
--- a/osu.Game.Rulesets.Mania/Resources/Testing/Beatmaps/mania-samples.osu
+++ b/osu.Game.Rulesets.Mania/Resources/Testing/Beatmaps/mania-samples.osu
@@ -13,6 +13,7 @@ SliderTickRate:1
 
 [TimingPoints]
 0,500,4,1,0,100,1,0
+10000,-150,4,1,0,100,1,0
 
 [HitObjects]
 51,192,500,128,0,1500:1:0:0:0:
diff --git a/osu.Game/Tests/Beatmaps/BeatmapConversionTest.cs b/osu.Game/Tests/Beatmaps/BeatmapConversionTest.cs
index 64f1ee4a7a..6d63525011 100644
--- a/osu.Game/Tests/Beatmaps/BeatmapConversionTest.cs
+++ b/osu.Game/Tests/Beatmaps/BeatmapConversionTest.cs
@@ -14,6 +14,7 @@ using osu.Framework.Graphics.Textures;
 using osu.Game.Beatmaps;
 using osu.Game.Beatmaps.Formats;
 using osu.Game.IO;
+using osu.Game.IO.Serialization;
 using osu.Game.Rulesets;
 using osu.Game.Rulesets.Mods;
 using osu.Game.Rulesets.Objects;
@@ -109,6 +110,8 @@ namespace osu.Game.Tests.Beatmaps
         {
             var beatmap = GetBeatmap(name);
 
+            string beforeConversion = beatmap.Serialize();
+
             var converterResult = new Dictionary<HitObject, IEnumerable<HitObject>>();
 
             var working = new ConversionWorkingBeatmap(beatmap)
@@ -122,6 +125,10 @@ namespace osu.Game.Tests.Beatmaps
 
             working.GetPlayableBeatmap(CreateRuleset().RulesetInfo, mods);
 
+            string afterConversion = beatmap.Serialize();
+
+            Assert.AreEqual(beforeConversion, afterConversion, "Conversion altered original beatmap");
+
             return new ConvertResult
             {
                 Mappings = converterResult.Select(r =>