diff --git a/idea/idea-analysis/src/org/jetbrains/kotlin/idea/search/searchUtil.kt b/idea/idea-analysis/src/org/jetbrains/kotlin/idea/search/searchUtil.kt
index 8fdc8d78622..985e772ceef 100644
--- a/idea/idea-analysis/src/org/jetbrains/kotlin/idea/search/searchUtil.kt
+++ b/idea/idea-analysis/src/org/jetbrains/kotlin/idea/search/searchUtil.kt
@@ -19,9 +19,7 @@ package org.jetbrains.kotlin.idea.search
 import com.intellij.openapi.fileTypes.FileType
 import com.intellij.openapi.fileTypes.FileTypeRegistry
 import com.intellij.openapi.progress.ProgressIndicator
-import com.intellij.openapi.progress.ProgressManager
 import com.intellij.openapi.project.Project
-import com.intellij.openapi.roots.FileIndexFacade
 import com.intellij.openapi.vfs.VirtualFile
 import com.intellij.psi.PsiElement
 import com.intellij.psi.PsiFile
@@ -32,15 +30,17 @@ import com.intellij.psi.search.LocalSearchScope
 import com.intellij.psi.search.PsiSearchHelper
 import com.intellij.psi.search.SearchScope
 import com.intellij.psi.search.searches.ReferencesSearch
-import com.intellij.util.Processor
+import com.intellij.util.CommonProcessors
 import com.intellij.util.indexing.FileBasedIndex
 import org.jetbrains.kotlin.idea.KotlinFileType
-import org.jetbrains.kotlin.idea.util.compat.psiSearchHelperInstance
 import org.jetbrains.kotlin.idea.util.application.runReadAction
+import org.jetbrains.kotlin.idea.util.compat.psiSearchHelperInstance
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.psi.KtFile
+import org.jetbrains.kotlin.psi.KtNamedDeclaration
 import org.jetbrains.kotlin.scripting.compiler.plugin.definitions.findScriptDefinition
 import org.jetbrains.kotlin.types.expressions.OperatorConventions
+import java.util.*
 
 infix fun SearchScope.and(otherScope: SearchScope): SearchScope = intersectWith(otherScope)
 infix fun SearchScope.or(otherScope: SearchScope): SearchScope = union(otherScope)
@@ -121,32 +121,23 @@ fun PsiSearchHelper.isCheapEnoughToSearchConsideringOperators(
         return PsiSearchHelper.SearchCostResult.TOO_MANY_OCCURRENCES
     }
 
-    if (!isCheapToSearchUsagesInScripts(scope.restrictToKotlinSources(), name)) {
-        return PsiSearchHelper.SearchCostResult.TOO_MANY_OCCURRENCES
-    }
-
     return isCheapEnoughToSearch(name, scope, fileToIgnoreOccurrencesIn, progress)
 }
 
-private fun isCheapToSearchUsagesInScripts(scope: GlobalSearchScope, name: String): Boolean {
-    val project = scope.project ?: return true
+fun findScriptsWithUsages(declaration: KtNamedDeclaration): List<VirtualFile> {
+    val project = declaration.project
+    val scope = psiSearchHelperInstance(project).getUseScope(declaration) as? GlobalSearchScope
+        ?: return emptyList()
 
-    var scriptsCount = 0
-    val processor = object : Processor<VirtualFile> {
-        override fun process(file: VirtualFile): Boolean {
-            ProgressManager.checkCanceled()
-            if (file.findScriptDefinition(project) == null) return true
-            return scriptsCount++ < 3
-        }
-    }
-
-    val index = FileIndexFacade.getInstance(project)
-    return runReadAction {
-        FileBasedIndex.getInstance().processFilesContainingAllKeys(
+    val name = declaration.name.takeIf { it?.isNotBlank() == true } ?: return emptyList()
+    val collector = CommonProcessors.CollectProcessor(ArrayList<VirtualFile>())
+    runReadAction {
+        FileBasedIndex.getInstance().getFilesWithKey(
             IdIndex.NAME,
-            listOf(IdIndexEntry(name, true)),
-            scope,
-            null,
-            { file -> !index.shouldBeFound(scope, file) || processor.process(file) })
+            setOf(IdIndexEntry(name, true)),
+            collector,
+            scope
+        )
     }
+    return collector.results.filter { it.findScriptDefinition(project) != null }.toList()
 }
diff --git a/idea/idea-core/src/org/jetbrains/kotlin/idea/core/script/ScriptDependenciesUpdater.kt b/idea/idea-core/src/org/jetbrains/kotlin/idea/core/script/ScriptDependenciesUpdater.kt
index af5ae9f8cdd..9765fb93005 100644
--- a/idea/idea-core/src/org/jetbrains/kotlin/idea/core/script/ScriptDependenciesUpdater.kt
+++ b/idea/idea-core/src/org/jetbrains/kotlin/idea/core/script/ScriptDependenciesUpdater.kt
@@ -75,6 +75,22 @@ class ScriptDependenciesUpdater(
         return cache[file] ?: ScriptDependencies.Empty
     }
 
+    fun updateDependenciesIfNeeded(files: List<VirtualFile>): Boolean {
+        val definitionsManager = ScriptDefinitionsManager.getInstance(project)
+        if (definitionsManager.isReady() && areDependenciesCached(files)) {
+            return false
+        }
+
+        for (file in files) {
+            val scriptDef = file.findScriptDefinition(project) ?: continue
+            updateDependencies(file, scriptDef)
+        }
+
+        makeRootsChangeIfNeeded()
+
+        return true
+    }
+
     private fun updateDependencies(file: VirtualFile, scriptDef: KotlinScriptDefinition) {
         val loader = when (scriptDef.dependencyResolver) {
             is AsyncDependenciesResolver, is LegacyResolverWrapper -> asyncLoader
@@ -154,6 +170,10 @@ class ScriptDependenciesUpdater(
         return cache[file] != null
     }
 
+    private fun areDependenciesCached(files: List<VirtualFile>): Boolean {
+        return files.all { areDependenciesCached(it) }
+    }
+
     companion object {
         @JvmStatic
         fun getInstance(project: Project): ScriptDependenciesUpdater =
diff --git a/idea/src/org/jetbrains/kotlin/idea/inspections/UnusedSymbolInspection.kt b/idea/src/org/jetbrains/kotlin/idea/inspections/UnusedSymbolInspection.kt
index 0d40d495d09..6d724a8063e 100644
--- a/idea/src/org/jetbrains/kotlin/idea/inspections/UnusedSymbolInspection.kt
+++ b/idea/src/org/jetbrains/kotlin/idea/inspections/UnusedSymbolInspection.kt
@@ -42,6 +42,7 @@ import org.jetbrains.kotlin.idea.caches.resolve.analyze
 import org.jetbrains.kotlin.idea.caches.resolve.findModuleDescriptor
 import org.jetbrains.kotlin.idea.caches.resolve.resolveToDescriptorIfAny
 import org.jetbrains.kotlin.idea.core.isInheritable
+import org.jetbrains.kotlin.idea.core.script.ScriptDependenciesUpdater
 import org.jetbrains.kotlin.idea.core.toDescriptor
 import org.jetbrains.kotlin.idea.findUsages.KotlinFindUsagesHandlerFactory
 import org.jetbrains.kotlin.idea.findUsages.handlers.KotlinFindClassUsagesHandler
@@ -52,6 +53,7 @@ import org.jetbrains.kotlin.idea.project.languageVersionSettings
 import org.jetbrains.kotlin.idea.quickfix.RemoveUnusedFunctionParameterFix
 import org.jetbrains.kotlin.idea.references.mainReference
 import org.jetbrains.kotlin.idea.references.resolveMainReferenceToDescriptors
+import org.jetbrains.kotlin.idea.search.findScriptsWithUsages
 import org.jetbrains.kotlin.idea.search.ideaExtensions.KotlinReferencesSearchOptions
 import org.jetbrains.kotlin.idea.search.ideaExtensions.KotlinReferencesSearchParameters
 import org.jetbrains.kotlin.idea.search.isCheapEnoughToSearchConsideringOperators
@@ -122,6 +124,13 @@ class UnusedSymbolInspection : AbstractKotlinInspection() {
             val project = declaration.project
             val psiSearchHelper = psiSearchHelperInstance(project)
 
+            val usedScripts = findScriptsWithUsages(declaration)
+            if (usedScripts.isNotEmpty()) {
+                if (ScriptDependenciesUpdater.getInstance(declaration.project).updateDependenciesIfNeeded(usedScripts)) {
+                    return TOO_MANY_OCCURRENCES
+                }
+            }
+
             val useScope = psiSearchHelper.getUseScope(declaration)
             if (useScope is GlobalSearchScope) {
                 var zeroOccurrences = true