diff --git a/src/xenia/apu/xma_context.cc b/src/xenia/apu/xma_context.cc
index e9047654a..91438bb57 100644
--- a/src/xenia/apu/xma_context.cc
+++ b/src/xenia/apu/xma_context.cc
@@ -320,7 +320,9 @@ void XmaContext::Decode(XMA_CONTEXT_DATA* data) {
 
   // No available data.
   if (!data->input_buffer_0_valid && !data->input_buffer_1_valid) {
-    data->output_buffer_valid = 0;
+    // 4156081D checks specifically for offset 0x20 when both input buffers
+    // are invalid.
+    data->input_buffer_read_offset = kBitsPerHeader;
     return;
   }
 
diff --git a/src/xenia/apu/xma_context.h b/src/xenia/apu/xma_context.h
index 52e97ee47..1ffdf9dba 100644
--- a/src/xenia/apu/xma_context.h
+++ b/src/xenia/apu/xma_context.h
@@ -134,7 +134,7 @@ class XmaContext {
  public:
   static const uint32_t kBytesPerPacket = 2048;
   static const uint32_t kBitsPerPacket = kBytesPerPacket * 8;
-  static const uint32_t kBitsPerHeader = 33;
+  static const uint32_t kBitsPerHeader = 32;
 
   static const uint32_t kBytesPerSample = 2;
   static const uint32_t kSamplesPerFrame = 512;