diff --git a/idea/idea-frontend-api/src/org/jetbrains/kotlin/idea/frontend/api/components/KtImportOptimizer.kt b/idea/idea-frontend-api/src/org/jetbrains/kotlin/idea/frontend/api/components/KtImportOptimizer.kt
index 3bc5a250c94..6d215640f15 100644
--- a/idea/idea-frontend-api/src/org/jetbrains/kotlin/idea/frontend/api/components/KtImportOptimizer.kt
+++ b/idea/idea-frontend-api/src/org/jetbrains/kotlin/idea/frontend/api/components/KtImportOptimizer.kt
@@ -5,10 +5,11 @@
 
 package org.jetbrains.kotlin.idea.frontend.api.components
 
+import org.jetbrains.kotlin.idea.frontend.api.ValidityTokenOwner
 import org.jetbrains.kotlin.psi.KtFile
 import org.jetbrains.kotlin.psi.KtImportDirective
 
-public abstract class KtImportOptimizer {
+public abstract class KtImportOptimizer : ValidityTokenOwner {
     public abstract fun analyseImports(file: KtFile): KtImportOptimizerResult
 }
 
diff --git a/idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/KtFirAnalysisSession.kt b/idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/KtFirAnalysisSession.kt
index d33330b1c87..074e781a136 100644
--- a/idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/KtFirAnalysisSession.kt
+++ b/idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/KtFirAnalysisSession.kt
@@ -64,7 +64,7 @@ private constructor(
 
     override val referenceShortenerImpl = KtFirReferenceShortener(this, token, firResolveState)
 
-    override val importOptimizerImpl: KtImportOptimizer = KtFirImportOptimizer(firResolveState)
+    override val importOptimizerImpl: KtImportOptimizer = KtFirImportOptimizer(token, firResolveState)
 
     override val symbolDeclarationRendererProviderImpl: KtSymbolDeclarationRendererProvider =
         KtFirSymbolDeclarationRendererProvider(this, token)
diff --git a/idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/components/KtFirImportOptimizer.kt b/idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/components/KtFirImportOptimizer.kt
index eda63526786..d99db920ea9 100644
--- a/idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/components/KtFirImportOptimizer.kt
+++ b/idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/components/KtFirImportOptimizer.kt
@@ -26,8 +26,10 @@ import org.jetbrains.kotlin.fir.visitors.FirVisitorVoid
 import org.jetbrains.kotlin.idea.fir.isInvokeFunction
 import org.jetbrains.kotlin.idea.fir.low.level.api.api.FirModuleResolveState
 import org.jetbrains.kotlin.idea.fir.low.level.api.api.getOrBuildFirFile
+import org.jetbrains.kotlin.idea.frontend.api.assertIsValidAndAccessible
 import org.jetbrains.kotlin.idea.frontend.api.components.KtImportOptimizer
 import org.jetbrains.kotlin.idea.frontend.api.components.KtImportOptimizerResult
+import org.jetbrains.kotlin.idea.frontend.api.tokens.ValidityToken
 import org.jetbrains.kotlin.name.ClassId
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.Name
@@ -38,12 +40,15 @@ import org.jetbrains.kotlin.resolve.ImportPath
 import org.jetbrains.kotlin.util.OperatorNameConventions
 
 internal class KtFirImportOptimizer(
+    override val token: ValidityToken,
     private val firResolveState: FirModuleResolveState
 ) : KtImportOptimizer() {
     private val firSession: FirSession
         get() = firResolveState.rootModuleSession
 
     override fun analyseImports(file: KtFile): KtImportOptimizerResult {
+        assertIsValidAndAccessible()
+
         val firFile = file.getOrBuildFirFile(firResolveState).apply { ensureResolved(FirResolvePhase.BODY_RESOLVE) }
 
         val existingImports = file.importDirectives