diff --git a/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/misc/JarUtils.kt b/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/misc/JarUtils.kt
index 7f445ca2..87ec9e80 100644
--- a/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/misc/JarUtils.kt
+++ b/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/misc/JarUtils.kt
@@ -78,7 +78,7 @@ public class JarUtils {
                             entry = stream.nextEntry
                         }
                     } else {
-                        val entryFileName = file.to(foundFile.path).path
+                        val entryFileName = file.to(foundFile.path).path.replace("\\", "/")
                         val entry = JarEntry(entryFileName)
                         entry.time = foundFile.lastModified()
                         addEntry(FileInputStream(localFile), entry, outputStream, onError)