diff --git a/OpenRA.Game/Graphics/SpriteCache.cs b/OpenRA.Game/Graphics/SpriteCache.cs
index 24e5f8cf77b4..463494de8934 100644
--- a/OpenRA.Game/Graphics/SpriteCache.cs
+++ b/OpenRA.Game/Graphics/SpriteCache.cs
@@ -93,9 +93,16 @@ public void LoadReservations(ModData modData)
 						{
 							var resolved = new Sprite[loadedFrames.Length];
 							resolvedSprites[token] = resolved;
-							var frames = rs.Frames ?? Enumerable.Range(0, loadedFrames.Length);
+							if (rs.Frames != null)
+							{
+								var frames = loadedFrames.Length;
+								foreach (var i in rs.Frames)
+									if (i >= frames)
+										throw new InvalidOperationException($"{rs.Location}: {filename} does not contain frames: " +
+										$"{string.Join(',', rs.Frames.Where(f => f >= frames))}");
+							}
 
-							foreach (var i in frames)
+							foreach (var i in rs.Frames ?? Enumerable.Range(0, loadedFrames.Length))
 							{
 								var frame = loadedFrames[i];
 								if (rs.AdjustFrame != null)