diff --git a/stepmania/src/PrefsManager.cpp b/stepmania/src/PrefsManager.cpp
index 1592e3ec9b..116e663b78 100644
--- a/stepmania/src/PrefsManager.cpp
+++ b/stepmania/src/PrefsManager.cpp
@@ -42,6 +42,7 @@ void PrefsManager::Init()
 	m_iRefreshRate = REFRESH_DEFAULT;
 	m_bOnlyDedicatedMenuButtons = false;
 	m_bCelShadeModels = false;		// Work-In-Progress.. disable by default.
+	m_fConstantUpdateDeltaSeconds = 0;
 #ifdef DEBUG
 	m_bShowStats = true;
 #else
@@ -330,6 +331,7 @@ void PrefsManager::ReadPrefsFromFile( CString sIni )
 	ini.GetValue( "Options", "ScreenHeight",					m_fScreenHeight );
 #endif
 	ini.GetValue( "Options", "CelShadeModels",					m_bCelShadeModels );
+	ini.GetValue( "Options", "ConstantUpdateDeltaSeconds",		m_fConstantUpdateDeltaSeconds );
 	ini.GetValue( "Options", "DisplayWidth",					m_iDisplayWidth );
 	ini.GetValue( "Options", "DisplayHeight",					m_iDisplayHeight );
 	ini.GetValue( "Options", "DisplayColorDepth",				m_iDisplayColorDepth );
@@ -563,6 +565,7 @@ void PrefsManager::SaveGlobalPrefsToDisk() const
 
 	ini.SetValue( "Options", "Windowed",						m_bWindowed );
 	ini.SetValue( "Options", "CelShadeModels",					m_bCelShadeModels );
+	ini.SetValue( "Options", "ConstantUpdateDeltaSeconds",		m_fConstantUpdateDeltaSeconds );
 	ini.SetValue( "Options", "DisplayWidth",					m_iDisplayWidth );
 	ini.SetValue( "Options", "DisplayHeight",					m_iDisplayHeight );
 	ini.SetValue( "Options", "DisplayColorDepth",				m_iDisplayColorDepth );
diff --git a/stepmania/src/PrefsManager.h b/stepmania/src/PrefsManager.h
index 01acd3f1c9..d9fe96c41f 100644
--- a/stepmania/src/PrefsManager.h
+++ b/stepmania/src/PrefsManager.h
@@ -202,6 +202,10 @@ public:
 	int				m_iMaxHighScoresPerListForPlayer;
 	bool			m_bCelShadeModels;
 
+	/* experimental: force a specific update rate.  This prevents big 
+	 * animation jumps on frame skips. */
+	float			m_fConstantUpdateDeltaSeconds;	// 0 to disable
+
 	// Number of seconds it takes for a button on the controller to release
 	// after pressed.
 	float			m_fPadStickSeconds;
diff --git a/stepmania/src/StepMania.cpp b/stepmania/src/StepMania.cpp
index b1af85483c..a95f893336 100644
--- a/stepmania/src/StepMania.cpp
+++ b/stepmania/src/StepMania.cpp
@@ -1496,6 +1496,9 @@ static void GameLoop()
 		 * Update
 		 */
 		float fDeltaTime = timer.GetDeltaTime();
+
+		if( PREFSMAN->m_fConstantUpdateDeltaSeconds > 0 )
+			fDeltaTime = PREFSMAN->m_fConstantUpdateDeltaSeconds;
 		
 		CheckSkips( fDeltaTime );