diff --git a/compiler/cli/src/org/jetbrains/kotlin/cli/jvm/index/JvmDependenciesIndexImpl.kt b/compiler/cli/src/org/jetbrains/kotlin/cli/jvm/index/JvmDependenciesIndexImpl.kt
index f3b33563796..e46f60491ac 100644
--- a/compiler/cli/src/org/jetbrains/kotlin/cli/jvm/index/JvmDependenciesIndexImpl.kt
+++ b/compiler/cli/src/org/jetbrains/kotlin/cli/jvm/index/JvmDependenciesIndexImpl.kt
@@ -20,10 +20,10 @@ import com.intellij.ide.highlighter.JavaClassFileType
 import com.intellij.ide.highlighter.JavaFileType
 import com.intellij.openapi.vfs.VfsUtilCore
 import com.intellij.openapi.vfs.VirtualFile
-import com.intellij.util.containers.IntArrayList
 import gnu.trove.THashMap
 import org.jetbrains.kotlin.name.ClassId
 import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.utils.IntArrayList
 import java.util.*
 
 // speeds up finding files/classes in classpath/java source roots
@@ -121,7 +121,7 @@ class JvmDependenciesIndexImpl(_roots: List<JavaRoot>) : JvmDependenciesIndex {
         // NOTE: indices manipulation instead of using caches.reversed() is here for performance reasons
         for (cacheIndex in caches.lastIndex downTo 0) {
             val cacheRootIndices = caches[cacheIndex].rootIndices
-            for (i in 0..cacheRootIndices.size() - 1) {
+            for (i in 0 until cacheRootIndices.size()) {
                 val rootIndex = cacheRootIndices[i]
                 if (rootIndex <= processedRootsUpTo) continue // roots with those indices have been processed by now
 
@@ -137,7 +137,7 @@ class JvmDependenciesIndexImpl(_roots: List<JavaRoot>) : JvmDependenciesIndex {
                     }
                 }
             }
-            processedRootsUpTo = if (cacheRootIndices.isEmpty) processedRootsUpTo else cacheRootIndices.get(cacheRootIndices.size() - 1)
+            processedRootsUpTo = if (cacheRootIndices.isEmpty) processedRootsUpTo else cacheRootIndices[cacheRootIndices.size() - 1]
         }
 
         if (request is FindClassRequest) {
@@ -156,7 +156,7 @@ class JvmDependenciesIndexImpl(_roots: List<JavaRoot>) : JvmDependenciesIndex {
         cachesPath: List<Cache>
     ): VirtualFile? {
         if (rootIndex >= maxIndex) {
-            for (i in (fillCachesAfter + 1)..(cachesPath.size - 1)) {
+            for (i in (fillCachesAfter + 1) until cachesPath.size) {
                 // we all know roots that contain this package by now
                 cachesPath[i].rootIndices.add(maxIndex)
                 cachesPath[i].rootIndices.trimToSize()
diff --git a/compiler/util/src/org/jetbrains/kotlin/utils/IntArrayList.kt b/compiler/util/src/org/jetbrains/kotlin/utils/IntArrayList.kt
new file mode 100644
index 00000000000..d718e32ccc2
--- /dev/null
+++ b/compiler/util/src/org/jetbrains/kotlin/utils/IntArrayList.kt
@@ -0,0 +1,38 @@
+/*
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.utils
+
+// Based on com.intellij.util.containers.IntArrayList.
+class IntArrayList(initialCapacity: Int) {
+    private var data = IntArray(initialCapacity)
+    private var size = 0
+
+    fun trimToSize() {
+        if (size < data.size) {
+            data = data.copyOf(size)
+        }
+    }
+
+    private fun ensureCapacity(minCapacity: Int) {
+        if (minCapacity > data.size) {
+            data = data.copyOf(maxOf(data.size * 3 / 2 + 1, minCapacity))
+        }
+    }
+
+    fun size(): Int = size
+
+    val isEmpty: Boolean get() = size == 0
+
+    operator fun get(index: Int): Int = data[index]
+
+    fun add(o: Int) {
+        ensureCapacity(size + 1)
+        data[size++] = o
+    }
+
+    override fun toString(): String =
+        (0 until size).joinToString(", ", "[", "]") { this[it].toString() }
+}