diff --git a/OpenRA.FileFormats/FileFormats/AudLoader.cs b/OpenRA.FileFormats/FileFormats/AudLoader.cs
index bf9a06410b..fe3abca8fe 100644
--- a/OpenRA.FileFormats/FileFormats/AudLoader.cs
+++ b/OpenRA.FileFormats/FileFormats/AudLoader.cs
@@ -76,7 +76,7 @@ namespace OpenRA.FileFormats
 			return (short)current;
 		}
 
-		public static byte[] LoadSound(byte[] raw)
+		public static byte[] LoadSound(byte[] raw, ref int index)
 		{
 			var br = new BinaryReader(new MemoryStream(raw));
 			var dataSize = raw.Length;
@@ -84,7 +84,6 @@ namespace OpenRA.FileFormats
 
 			var output = new byte[outputSize];
 			var offset = 0;
-			var index = 0;
 			var currentSample = 0;
 
 			while (dataSize-- > 0)
diff --git a/OpenRA.FileFormats/Graphics/VqaReader.cs b/OpenRA.FileFormats/Graphics/VqaReader.cs
index a38f140f89..91694e6dc8 100644
--- a/OpenRA.FileFormats/Graphics/VqaReader.cs
+++ b/OpenRA.FileFormats/Graphics/VqaReader.cs
@@ -132,7 +132,7 @@ namespace OpenRA.FileFormats
 						// Don't parse sound (yet); skip data
 						{
 							var rawAudio = reader.ReadBytes((int)length);
-							audioData = AudLoader.LoadSound(rawAudio);
+							audioData = AudLoader.LoadSound(rawAudio, ref adpcmIndex);
 						}
 						break;
 					case "VQFR":
@@ -147,7 +147,9 @@ namespace OpenRA.FileFormats
 			}
 			if (++currentFrame == Frames)
 				currentFrame = cbOffset = cbChunk = 0;
-		}
+		}
+
+		int adpcmIndex = 0;
 		
 		// VQA Frame
 		public void DecodeVQFR(BinaryReader reader)