diff --git a/build-common/src/org/jetbrains/kotlin/incremental/storage/IncrementalFileToPathConverter.kt b/build-common/src/org/jetbrains/kotlin/incremental/storage/IncrementalFileToPathConverter.kt
index 0e4bf9b6277..8f4441bbf00 100644
--- a/build-common/src/org/jetbrains/kotlin/incremental/storage/IncrementalFileToPathConverter.kt
+++ b/build-common/src/org/jetbrains/kotlin/incremental/storage/IncrementalFileToPathConverter.kt
@@ -27,6 +27,7 @@ open class IncrementalFileToPathConverter(val rootProjectDir: File?) : FileToPat
 
     private companion object {
         private const val PROJECT_DIR_PLACEHOLDER = "${'$'}PROJECT_DIR$"
+        //use only for prefix length because it OS dependent
         private const val PATH_PREFIX = "$PROJECT_DIR_PLACEHOLDER/"
 
     }
diff --git a/build-common/test/org/jetbrains/kotlin/incremental/storage/IncrementalFileToPathConverterTest.kt b/build-common/test/org/jetbrains/kotlin/incremental/storage/IncrementalFileToPathConverterTest.kt
index b049077b810..cfe017e0426 100644
--- a/build-common/test/org/jetbrains/kotlin/incremental/storage/IncrementalFileToPathConverterTest.kt
+++ b/build-common/test/org/jetbrains/kotlin/incremental/storage/IncrementalFileToPathConverterTest.kt
@@ -10,45 +10,46 @@ import org.junit.Test
 import java.io.File
 
 internal class IncrementalFileToPathConverterTest : TestWithWorkingDir() {
+    val separator: String = File.separator
 
     @Test
     fun testPathTransform() {
         val relativeFilePath = "testFile.txt"
         val transformedPath = testPathTransformation(workingDir.resolve("testDir"), relativeFilePath)
 
-        assertEquals("${'$'}PROJECT_DIR${'$'}/$relativeFilePath", transformedPath)
+        assertEquals("${'$'}PROJECT_DIR${'$'}$separator$relativeFilePath", transformedPath)
     }
 
     @Test
     fun testComplicatedProjectRootPath() {
         val relativeFilePath = "testFile.txt"
-        val transformedPath = testPathTransformation(workingDir.resolve("first/../testDir"), relativeFilePath)
+        val transformedPath = testPathTransformation(workingDir.resolve("first$separator..${separator}testDir"), relativeFilePath)
 
-        assertEquals("${'$'}PROJECT_DIR${'$'}/$relativeFilePath", transformedPath)
+        assertEquals("${'$'}PROJECT_DIR${'$'}$separator$relativeFilePath", transformedPath)
     }
 
     @Test
     fun testInccorectProjectRootPath() {
         val relativeFilePath = "testFile.txt"
-        val transformedPath = testPathTransformation(workingDir.resolve("testDir/"), relativeFilePath)
+        val transformedPath = testPathTransformation(workingDir.resolve("testDir$separator"), relativeFilePath)
 
-        assertEquals("${'$'}PROJECT_DIR${'$'}/$relativeFilePath", transformedPath)
+        assertEquals("${'$'}PROJECT_DIR${'$'}$separator$relativeFilePath", transformedPath)
     }
 
     @Test
     fun testFileOutOfProject() {
-        val relativeFilePath = "../testFile.txt"
+        val relativeFilePath = "..${separator}testFile.txt"
         val transformedPath = testPathTransformation(workingDir.resolve("testDir"), relativeFilePath)
 
-        assertEquals("${workingDir.absolutePath}/testFile.txt", transformedPath)
+        assertEquals("${workingDir.absolutePath}${separator}testFile.txt", transformedPath)
     }
 
     @Test
     fun testFileWithExtraSlash() {
-        val relativeFilePath = "testFile.txt/"
+        val relativeFilePath = "testFile.txt$separator"
         val transformedPath = testPathTransformation(workingDir.resolve("testDir"), relativeFilePath)
 
-        assertEquals("${'$'}PROJECT_DIR${'$'}/testFile.txt", transformedPath)
+        assertEquals("${'$'}PROJECT_DIR${'$'}${separator}testFile.txt", transformedPath)
     }
 
     private fun testPathTransformation(projectRoot: File, relativeFilePath: String): String {