diff --git a/OpenRA.Game/Graphics/Renderer.cs b/OpenRA.Game/Graphics/Renderer.cs
index 04133779ab..6880fa30df 100644
--- a/OpenRA.Game/Graphics/Renderer.cs
+++ b/OpenRA.Game/Graphics/Renderer.cs
@@ -37,6 +37,8 @@ namespace OpenRA.Graphics
 		readonly Queue<IVertexBuffer<Vertex>> tempBuffers = new Queue<IVertexBuffer<Vertex>>();
 		readonly Stack<Rectangle> scissorState = new Stack<Rectangle>();
 
+		SheetBuilder fontSheetBuilder;
+
 		Size? lastResolution;
 		int2? lastScroll;
 		float? lastZoom;
@@ -94,8 +96,13 @@ namespace OpenRA.Graphics
 		public void InitializeFonts(Manifest m)
 		{
 			using (new Support.PerfTimer("SpriteFonts"))
+			{
+				if (fontSheetBuilder != null)
+					fontSheetBuilder.Dispose();
+				fontSheetBuilder = new SheetBuilder(SheetType.BGRA);
 				Fonts = m.Fonts.ToDictionary(x => x.Key,
-					x => new SpriteFont(Platform.ResolvePath(x.Value.First), x.Value.Second)).AsReadOnly();
+					x => new SpriteFont(Platform.ResolvePath(x.Value.First), x.Value.Second, fontSheetBuilder)).AsReadOnly();
+			}
 		}
 
 		public void BeginFrame(int2 scroll, float zoom)
@@ -246,6 +253,8 @@ namespace OpenRA.Graphics
 			foreach (var buffer in tempBuffers)
 				buffer.Dispose();
 			tempBuffers.Clear();
+			if (fontSheetBuilder != null)
+				fontSheetBuilder.Dispose();
 		}
 	}
 }
diff --git a/OpenRA.Game/Graphics/SheetBuilder.cs b/OpenRA.Game/Graphics/SheetBuilder.cs
index 10644f58fc..5817f91f53 100644
--- a/OpenRA.Game/Graphics/SheetBuilder.cs
+++ b/OpenRA.Game/Graphics/SheetBuilder.cs
@@ -31,8 +31,8 @@ namespace OpenRA.Graphics
 
 	public sealed class SheetBuilder : IDisposable
 	{
+		public readonly SheetType Type;
 		readonly List<Sheet> sheets = new List<Sheet>();
-		readonly SheetType type;
 		readonly Func<Sheet> allocateSheet;
 
 		Sheet current;
@@ -54,7 +54,7 @@ namespace OpenRA.Graphics
 		public SheetBuilder(SheetType t, Func<Sheet> allocateSheet)
 		{
 			channel = TextureChannel.Red;
-			type = t;
+			Type = t;
 			current = allocateSheet();
 			sheets.Add(current);
 			this.allocateSheet = allocateSheet;
@@ -93,7 +93,7 @@ namespace OpenRA.Graphics
 
 		TextureChannel? NextChannel(TextureChannel t)
 		{
-			var nextChannel = (int)t + (int)type;
+			var nextChannel = (int)t + (int)Type;
 			if (nextChannel > (int)TextureChannel.Alpha)
 				return null;
 
diff --git a/OpenRA.Game/Graphics/SpriteFont.cs b/OpenRA.Game/Graphics/SpriteFont.cs
index af409a0910..b2d1905448 100644
--- a/OpenRA.Game/Graphics/SpriteFont.cs
+++ b/OpenRA.Game/Graphics/SpriteFont.cs
@@ -19,26 +19,27 @@ namespace OpenRA.Graphics
 {
 	public class SpriteFont
 	{
-		static Library library = new Library();
-		static SheetBuilder builder;
+		static readonly Library Library = new Library();
 
 		readonly int size;
-
+		readonly SheetBuilder builder;
 		readonly Func<string, float> lineWidth;
+		readonly Face face;
+		readonly Cache<Pair<char, Color>, GlyphInfo> glyphs;
 
-		public SpriteFont(string name, int size)
+		public SpriteFont(string name, int size, SheetBuilder builder)
 		{
-			this.size = size;
+			if (builder.Type != SheetType.BGRA)
+				throw new ArgumentException("The sheet builder must create BGRA sheets.", "builder");
 
-			face = new Face(library, name);
+			this.size = size;
+			this.builder = builder;
+
+			face = new Face(Library, name);
 			face.SetPixelSizes((uint)size, (uint)size);
 
 			glyphs = new Cache<Pair<char, Color>, GlyphInfo>(CreateGlyph, Pair<char, Color>.EqualityComparer);
 
-			// setup a SheetBuilder for our private use
-			// TODO: SheetBuilder state is leaked between mod switches
-			if (builder == null)
-				builder = new SheetBuilder(SheetType.BGRA);
 			Func<char, float> characterWidth = character => glyphs[Pair.New(character, Color.White)].Advance;
 			lineWidth = line => line.Sum(characterWidth);
 
@@ -96,9 +97,6 @@ namespace OpenRA.Graphics
 			return new int2((int)Math.Ceiling(lines.Max(lineWidth)), lines.Length * size);
 		}
 
-		Cache<Pair<char, Color>, GlyphInfo> glyphs;
-		Face face;
-
 		GlyphInfo CreateGlyph(Pair<char, Color> c)
 		{
 			face.LoadChar(c.First, LoadFlags.Default, LoadTarget.Normal);