diff --git a/sim/core/apl.go b/sim/core/apl.go
index 88741763e5..fe2dd4a6ac 100644
--- a/sim/core/apl.go
+++ b/sim/core/apl.go
@@ -14,7 +14,7 @@ type APLRotation struct {
 	priorityList   []*APLAction
 
 	// Action currently controlling this rotation (only used for certain actions, such as StrictSequence).
-	controllingAction APLActionImpl
+	controllingActions []APLActionImpl
 
 	// Value that should evaluate to 'true' if the current channel is to be interrupted.
 	// Will be nil when there is no active channel.
@@ -166,7 +166,7 @@ func (rot *APLRotation) allPrepullActions() []*APLAction {
 }
 
 func (rot *APLRotation) reset(sim *Simulation) {
-	rot.controllingAction = nil
+	rot.controllingActions = nil
 	rot.inLoop = false
 	rot.interruptChannelIf = nil
 	rot.allowChannelRecastOnInterrupt = false
@@ -219,8 +219,8 @@ func (apl *APLRotation) DoNextAction(sim *Simulation) {
 }
 
 func (apl *APLRotation) getNextAction(sim *Simulation) *APLAction {
-	if apl.controllingAction != nil {
-		return apl.controllingAction.GetNextAction(sim)
+	if len(apl.controllingActions) != 0 {
+		return apl.controllingActions[len(apl.controllingActions)-1].GetNextAction(sim)
 	}
 
 	for _, action := range apl.priorityList {
@@ -232,6 +232,17 @@ func (apl *APLRotation) getNextAction(sim *Simulation) *APLAction {
 	return nil
 }
 
+func (apl *APLRotation) pushControllingAction(ca APLActionImpl) {
+	apl.controllingActions = append(apl.controllingActions, ca)
+}
+
+func (apl *APLRotation) popControllingAction(ca APLActionImpl) {
+	if len(apl.controllingActions) == 0 || apl.controllingActions[len(apl.controllingActions)-1] != ca {
+		panic("Wrong APL controllingAction in pop()")
+	}
+	apl.controllingActions = apl.controllingActions[:len(apl.controllingActions)-1]
+}
+
 func (apl *APLRotation) shouldInterruptChannel(sim *Simulation) bool {
 	channeledDot := apl.unit.ChanneledDot
 
diff --git a/sim/core/apl_actions_sequences.go b/sim/core/apl_actions_sequences.go
index a754413078..a2cfb4d27f 100644
--- a/sim/core/apl_actions_sequences.go
+++ b/sim/core/apl_actions_sequences.go
@@ -136,7 +136,7 @@ func (action *APLActionStrictSequence) IsReady(sim *Simulation) bool {
 	return true
 }
 func (action *APLActionStrictSequence) Execute(sim *Simulation) {
-	action.unit.Rotation.controllingAction = action
+	action.unit.Rotation.pushControllingAction(action)
 }
 func (action *APLActionStrictSequence) GetNextAction(sim *Simulation) *APLAction {
 	if action.subactions[action.curIdx].IsReady(sim) {
@@ -145,7 +145,7 @@ func (action *APLActionStrictSequence) GetNextAction(sim *Simulation) *APLAction
 		action.curIdx++
 		if action.curIdx == len(action.subactions) {
 			action.curIdx = 0
-			action.unit.Rotation.controllingAction = nil
+			action.unit.Rotation.popControllingAction(action)
 		}
 
 		return nextAction
@@ -153,7 +153,7 @@ func (action *APLActionStrictSequence) GetNextAction(sim *Simulation) *APLAction
 		// If the GCD is ready when the next subaction isn't, it means the sequence is bad
 		// so reset and exit the sequence.
 		action.curIdx = 0
-		action.unit.Rotation.controllingAction = nil
+		action.unit.Rotation.popControllingAction(action)
 		return action.unit.Rotation.getNextAction(sim)
 	} else {
 		// Return nil to wait for the GCD to become ready.
diff --git a/sim/core/apl_actions_timing.go b/sim/core/apl_actions_timing.go
index 77e520c2a3..3552133d52 100644
--- a/sim/core/apl_actions_timing.go
+++ b/sim/core/apl_actions_timing.go
@@ -36,7 +36,7 @@ func (action *APLActionWait) IsReady(sim *Simulation) bool {
 }
 
 func (action *APLActionWait) Execute(sim *Simulation) {
-	action.unit.Rotation.controllingAction = action
+	action.unit.Rotation.pushControllingAction(action)
 	action.curWaitTime = sim.CurrentTime + action.duration.GetDuration(sim)
 
 	pa := &PendingAction{
@@ -49,7 +49,7 @@ func (action *APLActionWait) Execute(sim *Simulation) {
 
 func (action *APLActionWait) GetNextAction(sim *Simulation) *APLAction {
 	if sim.CurrentTime >= action.curWaitTime {
-		action.unit.Rotation.controllingAction = nil
+		action.unit.Rotation.popControllingAction(action)
 		return action.unit.Rotation.getNextAction(sim)
 	} else {
 		return nil
@@ -86,12 +86,12 @@ func (action *APLActionWaitUntil) IsReady(sim *Simulation) bool {
 }
 
 func (action *APLActionWaitUntil) Execute(sim *Simulation) {
-	action.unit.Rotation.controllingAction = action
+	action.unit.Rotation.pushControllingAction(action)
 }
 
 func (action *APLActionWaitUntil) GetNextAction(sim *Simulation) *APLAction {
 	if action.condition.GetBool(sim) {
-		action.unit.Rotation.controllingAction = nil
+		action.unit.Rotation.popControllingAction(action)
 		return action.unit.Rotation.getNextAction(sim)
 	} else {
 		return nil