diff --git a/stepmania/src/RageThreads.cpp b/stepmania/src/RageThreads.cpp
index bc8211f195..0775923fd4 100644
--- a/stepmania/src/RageThreads.cpp
+++ b/stepmania/src/RageThreads.cpp
@@ -79,11 +79,13 @@ LockMutex::LockMutex(RageMutex &mut, const char *file_, int line_):
 	locked_at(RageTimer::GetTimeSinceStart())
 {
 	mutex.Lock();
+	locked = true;
 }
 
 LockMutex::~LockMutex()
 {
-	mutex.Unlock();
+	if(locked)
+		mutex.Unlock();
 
 	if(file)
 	{
@@ -93,6 +95,15 @@ LockMutex::~LockMutex()
 	}
 }
 
+void LockMutex::Unlock()
+{
+	ASSERT(locked);
+	locked = false;
+
+	mutex.Unlock();
+}
+
+
 /*
 -----------------------------------------------------------------------------
  File: RageThreads
diff --git a/stepmania/src/RageThreads.h b/stepmania/src/RageThreads.h
index 0ae02abeeb..a220d2986e 100644
--- a/stepmania/src/RageThreads.h
+++ b/stepmania/src/RageThreads.h
@@ -30,12 +30,17 @@ class LockMutex
 	const char *file;
 	int line;
 	float locked_at;
+	bool locked;
 
 public:
 	LockMutex(RageMutex &mut, const char *file, int line);
 	LockMutex(RageMutex &mut): mutex(mut), file(NULL), line(-1), locked_at(0) { mutex.Lock(); }
 	~LockMutex();
 	LockMutex(LockMutex &cpy): mutex(cpy.mutex), file(cpy.file), line(cpy.line), locked_at(cpy.locked_at) { mutex.Lock(); }
+
+	/* Unlock the mutex (before this would normally go out of scope).  This can
+	 * only be called once. */
+	void Unlock();
 };
 
 /* Double-abstracting __LINE__ lets us append it to other text, to generate