diff --git a/reactor/Core/src/jetbrains/mps/logic/reactor/core/Occurrence.kt b/reactor/Core/src/jetbrains/mps/logic/reactor/core/Occurrence.kt
index 4a56c17e..e266f64f 100644
--- a/reactor/Core/src/jetbrains/mps/logic/reactor/core/Occurrence.kt
+++ b/reactor/Core/src/jetbrains/mps/logic/reactor/core/Occurrence.kt
@@ -65,11 +65,9 @@ class Occurrence (observable: LogicalStateObservable,
     override fun parentUpdated(logical: Logical<*>, controller: Controller) = doReactivate(controller)
 
     fun terminate(observable: LogicalStateObservable) {
-        if (alive) {
-            for (a in arguments) {
-                if (a is Logical<*>) {
-                    observable.removeForwardingObserver(a, this)
-                }
+        for (a in arguments) {
+            if (a is Logical<*>) {
+                observable.removeForwardingObserver(a, this)
             }
         }
         alive = false
diff --git a/reactor/Core/src/jetbrains/mps/logic/reactor/core/internal/EvaluationSessionImpl.kt b/reactor/Core/src/jetbrains/mps/logic/reactor/core/internal/EvaluationSessionImpl.kt
index 5730fad5..54ea9e40 100644
--- a/reactor/Core/src/jetbrains/mps/logic/reactor/core/internal/EvaluationSessionImpl.kt
+++ b/reactor/Core/src/jetbrains/mps/logic/reactor/core/internal/EvaluationSessionImpl.kt
@@ -211,10 +211,10 @@ internal class EvaluationSessionImpl private constructor (
             val outputOccurrences = histView.filterOccurrences(inputStore)
             // todo: make output store in other processing strategies?
 
+            outputOccurrences.forEach{ it.terminate(logicalState) }
             processing.resetStore() // clear observers
             // todo: need clearing occurrenceContractObservers? (MPSCR-66)
             logicalState.reset()
-            outputOccurrences.forEach{ it.terminate(logicalState) }
 
             val rules = ruleIndex.toRules().filter(preambleInfo::inPreamble)