diff --git a/reactor/Core/src/jetbrains/mps/logic/reactor/core/internal/ReteRuleMatcherImpl.kt b/reactor/Core/src/jetbrains/mps/logic/reactor/core/internal/ReteRuleMatcherImpl.kt
index 2ad406e7..457f7c1e 100644
--- a/reactor/Core/src/jetbrains/mps/logic/reactor/core/internal/ReteRuleMatcherImpl.kt
+++ b/reactor/Core/src/jetbrains/mps/logic/reactor/core/internal/ReteRuleMatcherImpl.kt
@@ -530,7 +530,7 @@ internal class ReteRuleMatcherImpl(private var ruleLookup: RuleLookup,
         }
 
         override fun forget(ruleMatch: RuleMatchEx): RuleMatchingProbe {
-            consumedSignatures.add(ruleMatch.signatureArray().toSignature())
+            consumedSignatures.remove(ruleMatch.signatureArray().toSignature())
             return this
         }