diff --git a/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/JarGenerator.kt b/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/JarGenerator.kt
index 61acb1e1..9572a622 100644
--- a/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/JarGenerator.kt
+++ b/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/JarGenerator.kt
@@ -150,7 +150,7 @@ class JarGenerator @Inject constructor(val dependencyManager: DependencyManager)
                     context.logger.log(project.name, 2, "Including MANIFEST.MF file $manifestFile")
                     Manifest(FileInputStream(manifestFile))
                 } else {
-                    Manifest()
+                    null
                 }
             }