diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/npm/NpmProject.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/npm/NpmProject.kt
index 8f52a554586..c6d3bc26960 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/npm/NpmProject.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/npm/NpmProject.kt
@@ -78,7 +78,7 @@ open class NpmProject(@Transient val compilation: KotlinJsCompilation) : Seriali
         get() = dir.resolve(DIST_FOLDER)
 
     val main: String
-        get() = "$DIST_FOLDER${File.separator}$name$extension"
+        get() = "${DIST_FOLDER}/$name$extension"
 
     val publicPackageJsonTaskName: String
         get() = compilation.disambiguateName(PublicPackageJsonTask.NAME)