diff --git a/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/archive/MetaArchive.kt b/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/archive/MetaArchive.kt
index 29f05a43..fc121231 100644
--- a/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/archive/MetaArchive.kt
+++ b/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/archive/MetaArchive.kt
@@ -64,7 +64,7 @@ class MetaArchive(private val outputFile: File, val manifest: Manifest?) : Close
     }
 
     private val DEFAULT_JAR_EXCLUDES =
-            Glob("META-INF/*.SF", "META-INF/*.DSA", "META-INF/*.RSA")
+            Glob("META-INF/*.SF", "META-INF/*.DSA", "META-INF/*.RSA", "META-INF/MANIFEST.MF")
 
     private val seen = hashSetOf<String>()
 
diff --git a/src/main/kotlin/com/beust/kobalt/plugin/osgi/OsgiPlugin.kt b/src/main/kotlin/com/beust/kobalt/plugin/osgi/OsgiPlugin.kt
index 8a2a06b8..83ae5228 100644
--- a/src/main/kotlin/com/beust/kobalt/plugin/osgi/OsgiPlugin.kt
+++ b/src/main/kotlin/com/beust/kobalt/plugin/osgi/OsgiPlugin.kt
@@ -90,7 +90,10 @@ class OsgiPlugin @Inject constructor(val configActor: ConfigActor<OsgiConfig>, v
             val fileSystem = FileSystems.newFileSystem(toFile, null)
             fileSystem.use { fs ->
                 JarFile(jarFile).use { jf ->
-                    val mf = jf.getEntry(MetaArchive.MANIFEST_MF) ?: Files.createDirectories(fs.getPath("META-INF/"))
+                    val mf = jf.getEntry(MetaArchive.MANIFEST_MF)
+                    if (mf == null) {
+                        Files.createDirectories(fs.getPath("META-INF/"))
+                    }
                     val jarManifest = fs.getPath(MetaArchive.MANIFEST_MF)
                     Files.write(jarManifest, listOf(lines2),
                             if (mf != null) StandardOpenOption.APPEND else StandardOpenOption.CREATE)