diff --git a/OpenRA.FileFormats/Primitives/Pair.cs b/OpenRA.FileFormats/Primitives/Pair.cs
index 60f67df522..7603795801 100644
--- a/OpenRA.FileFormats/Primitives/Pair.cs
+++ b/OpenRA.FileFormats/Primitives/Pair.cs
@@ -60,7 +60,15 @@ namespace OpenRA.FileFormats
 		public override string ToString()
 		{
 			return "({0},{1})".F(First, Second);
-		}
+		}
+
+		class PairEqualityComparer : IEqualityComparer<Pair<T, U>>
+		{
+			public bool Equals(Pair<T, U> x, Pair<T, U> y) { return x == y; }
+			public int GetHashCode(Pair<T, U> obj) { return obj.GetHashCode(); }
+		}
+
+		public static IEqualityComparer<Pair<T, U>> EqualityComparer { get { return new PairEqualityComparer(); } }
 	}
 
     public static class Pair
diff --git a/OpenRA.Game/Graphics/SpriteFont.cs b/OpenRA.Game/Graphics/SpriteFont.cs
index 8ba3cd9d24..4dbaf0b01c 100644
--- a/OpenRA.Game/Graphics/SpriteFont.cs
+++ b/OpenRA.Game/Graphics/SpriteFont.cs
@@ -29,7 +29,8 @@ namespace OpenRA.Graphics
 				throw new InvalidOperationException("FT_New_Face failed");
 
 			FT.FT_Set_Pixel_Sizes(face, 0, (uint)size);
-			glyphs = new Cache<Pair<char, Color>, GlyphInfo>(CreateGlyph);
+			glyphs = new Cache<Pair<char, Color>, GlyphInfo>(CreateGlyph,
+				Pair<char,Color>.EqualityComparer);
 
 			// setup a 1-channel SheetBuilder for our private use
 			if (builder == null) builder = new SheetBuilder(TextureChannel.Alpha);