diff --git a/libraries/tools/kotlin-maven-plugin/src/main/java/org/jetbrains/kotlin/maven/JSSourceJarMojo.java b/libraries/tools/kotlin-maven-plugin/src/main/java/org/jetbrains/kotlin/maven/JSSourceJarMojo.java
index 8f736da115f..15ae9c920c5 100644
--- a/libraries/tools/kotlin-maven-plugin/src/main/java/org/jetbrains/kotlin/maven/JSSourceJarMojo.java
+++ b/libraries/tools/kotlin-maven-plugin/src/main/java/org/jetbrains/kotlin/maven/JSSourceJarMojo.java
@@ -73,7 +73,7 @@ public class JSSourceJarMojo extends AbstractMojo {
                         if (fullPath.startsWith(rootPath)) {
                             String relativePath = fullPath.substring(rootPath.length());
                             if (relativePath.startsWith("/") || relativePath.startsWith(File.separator)) {
-                                relativePath = relativePath.substring(1);
+                                relativePath = relativePath.substring(1).replace(File.separatorChar, '/');
                             }
                             writer.println(relativePath);
                         } else {