diff --git a/src/g_shared/a_quake.cpp b/src/g_shared/a_quake.cpp
index 38cff2d2dc..91d654d02f 100644
--- a/src/g_shared/a_quake.cpp
+++ b/src/g_shared/a_quake.cpp
@@ -80,7 +80,6 @@ void DEarthquake::Serialize (FArchive &arc)
 	{
 		arc << m_CountdownStart;
 	}
-	
 }
 
 //==========================================================================
@@ -101,7 +100,7 @@ void DEarthquake::Tick ()
 		Destroy ();
 		return;
 	}
-
+	
 	if (!S_IsActorPlayingSomething (m_Spot, CHAN_BODY, m_QuakeSFX))
 	{
 		S_Sound (m_Spot, CHAN_BODY | CHAN_LOOP, m_QuakeSFX, 1, ATTN_NORM);
@@ -141,6 +140,7 @@ void DEarthquake::Tick ()
 			}
 		}
 	}
+	
 	if (--m_Countdown == 0)
 	{
 		if (S_IsActorPlayingSomething(m_Spot, CHAN_BODY, m_QuakeSFX))
@@ -166,7 +166,7 @@ int DEarthquake::StaticGetQuakeIntensities(AActor *victim, quakeInfo &qprop)
 	{
 		return 0;
 	}
-
+	qprop.isScalingDown = qprop.isScalingUp = false, qprop.preferMaximum = false;
 	qprop.intensityX = qprop.intensityY = qprop.intensityZ = qprop.relIntensityX = qprop.relIntensityY = qprop.relIntensityZ = 0;
 
 	TThinkerIterator<DEarthquake> iterator(STAT_EARTHQUAKE);
@@ -194,10 +194,13 @@ int DEarthquake::StaticGetQuakeIntensities(AActor *victim, quakeInfo &qprop)
 					qprop.intensityY = MAX(qprop.intensityY, quake->m_IntensityY);
 					qprop.intensityZ = MAX(qprop.intensityZ, quake->m_IntensityZ);
 				}
-				if (quake->m_Flags & QF_SCALEDOWN)
+				if (quake->m_Flags)
 				{
 					qprop.scaleDownStart = quake->m_CountdownStart;
 					qprop.scaleDown = quake->m_Countdown;
+					qprop.isScalingDown = (quake->m_Flags & QF_SCALEDOWN) ? true : false;
+					qprop.isScalingUp = (quake->m_Flags & QF_SCALEUP) ? true : false;
+					qprop.preferMaximum = (quake->m_Flags & QF_MAX) ? true : false;
 				}
 				else
 				{
diff --git a/src/g_shared/a_sharedglobal.h b/src/g_shared/a_sharedglobal.h
index 3ae80040e9..2f34f9f5af 100644
--- a/src/g_shared/a_sharedglobal.h
+++ b/src/g_shared/a_sharedglobal.h
@@ -136,12 +136,14 @@ enum
 	QF_RELATIVE =	1,
 	QF_SCALEDOWN =	1 << 1,
 	QF_SCALEUP =	1 << 2,
+	QF_MAX =		1 << 3,
 };
 
 struct quakeInfo
 {
 	int intensityX, intensityY, intensityZ, relIntensityX, relIntensityY, relIntensityZ;
 	double scaleDown, scaleDownStart;
+	bool isScalingDown, isScalingUp, preferMaximum;
 };
 
 class DEarthquake : public DThinker
diff --git a/src/r_utility.cpp b/src/r_utility.cpp
index d27eeaca86..42581add5f 100644
--- a/src/r_utility.cpp
+++ b/src/r_utility.cpp
@@ -781,13 +781,31 @@ static fixed_t QuakePower(double factor, int intensity, quakeInfo quake)
 	else
 	{
 		double ss = (double)((pr_torchflicker() % (intensity << 2)) - (intensity << 1));
-		if (scaleDownStart == 0)
+		
+		if (quake.isScalingDown || quake.isScalingUp)
 		{
-			return FLOAT2FIXED(factor * ss);
+			fixed_t result;
+			if (scaleDownStart == 0)	scaleDownStart = 1;
+
+			if (quake.isScalingDown && quake.isScalingUp)
+			{
+				if (quake.preferMaximum)
+					result = FLOAT2FIXED((factor * ss) * MAX((scaleDown / scaleDownStart), (scaleDownStart - scaleDown) / scaleDownStart));
+				else
+					result = FLOAT2FIXED((factor * ss) * MIN((scaleDown / scaleDownStart), (scaleDownStart - scaleDown) / scaleDownStart));
+			}
+			else if (quake.isScalingDown)
+				result = FLOAT2FIXED((factor * ss) * (scaleDown / scaleDownStart));
+			else if (quake.isScalingUp)
+				result = FLOAT2FIXED((factor * ss) * ((scaleDownStart - scaleDown) / scaleDownStart));
+			else
+				result = FLOAT2FIXED(factor * ss);
+
+			return result;
 		}
 		else
 		{
-			return FLOAT2FIXED(((factor * ss) * ((scaleDown / scaleDownStart))));
+			return FLOAT2FIXED(factor * ss);
 		}
 	}
 	
diff --git a/wadsrc/static/actors/constants.txt b/wadsrc/static/actors/constants.txt
index 19845b91d4..e245c37efb 100644
--- a/wadsrc/static/actors/constants.txt
+++ b/wadsrc/static/actors/constants.txt
@@ -464,6 +464,7 @@ enum
 	QF_RELATIVE =		1,
 	QF_SCALEDOWN =		1 << 1,
 	QF_SCALEUP =		1 << 2,
+	QF_MAX =			1 << 3,
 };
 
 // This is only here to provide one global variable for testing.