diff --git a/compiler/visualizer/tests/org/jetbrains/kotlin/visualizer/AbstractVisualizer.kt b/compiler/visualizer/tests/org/jetbrains/kotlin/visualizer/AbstractVisualizer.kt
index 10dedaeab32..04cee40c061 100644
--- a/compiler/visualizer/tests/org/jetbrains/kotlin/visualizer/AbstractVisualizer.kt
+++ b/compiler/visualizer/tests/org/jetbrains/kotlin/visualizer/AbstractVisualizer.kt
@@ -38,7 +38,7 @@ abstract class AbstractVisualizer : KotlinMultiFileTestWithJava<Void?, Void?>()
     }
 
     fun doFirBuilderDataTest(filePath: String) {
-        replacement = "fir\\psi2fir" to "visualizer"
+        replacement = "fir${File.separator}psi2fir" to "visualizer"
         doTest(filePath)
     }