diff --git a/compiler/tests/org/jetbrains/jet/codegen/CodegenTestCase.java b/compiler/tests/org/jetbrains/jet/codegen/CodegenTestCase.java
index 6114fd05da0..94217cb3e67 100644
--- a/compiler/tests/org/jetbrains/jet/codegen/CodegenTestCase.java
+++ b/compiler/tests/org/jetbrains/jet/codegen/CodegenTestCase.java
@@ -111,8 +111,9 @@ public abstract class CodegenTestCase extends UsefulTestCase {
     @NotNull
     protected String relativePath(@NotNull File file) {
         String stringToCut = "compiler/testData/codegen/";
-        assert file.getPath().startsWith(stringToCut) : "File path is not absolute: " + file;
-        return file.getPath().substring(stringToCut.length());
+        String systemIndependentPath = file.getPath().replace(File.separatorChar, '/');
+        assert systemIndependentPath.startsWith(stringToCut) : "File path is not absolute: " + file;
+        return systemIndependentPath.substring(stringToCut.length());
     }
 
     @NotNull