diff --git a/Core/CoreTiming.cpp b/Core/CoreTiming.cpp
index 57093d17ae..7b25787fdc 100644
--- a/Core/CoreTiming.cpp
+++ b/Core/CoreTiming.cpp
@@ -189,6 +189,7 @@ void AntiCrashCallback(u64 userdata, int cyclesLate)
 
 void RestoreRegisterEvent(int event_type, const char *name, TimedCallback callback)
 {
+	_assert_msg_(CORETIMING, event_type >= 0, "Invalid event type %d", event_type)
 	if (event_type >= (int) event_types.size())
 		event_types.resize(event_type + 1, EventType(AntiCrashCallback, "INVALID EVENT"));
 
diff --git a/Core/HLE/sceSas.cpp b/Core/HLE/sceSas.cpp
index 5c4c71a92b..3dd69b5b94 100644
--- a/Core/HLE/sceSas.cpp
+++ b/Core/HLE/sceSas.cpp
@@ -207,11 +207,14 @@ void __SasDoState(PointerWrap &p) {
 
 	if (s >= 2) {
 		p.Do(sasMixEvent);
-		CoreTiming::RestoreRegisterEvent(sasMixEvent, "SasMix", sasMixFinish);
 	} else {
 		sasMixEvent = -1;
 		__SasDisableThread();
 	}
+
+	if (sasMixEvent != -1) {
+		CoreTiming::RestoreRegisterEvent(sasMixEvent, "SasMix", sasMixFinish);
+	}
 }
 
 void __SasShutdown() {