diff --git a/com.google.eclipse.protobuf/META-INF/MANIFEST.MF b/com.google.eclipse.protobuf/META-INF/MANIFEST.MF
index cbe1187..a7191ae 100644
--- a/com.google.eclipse.protobuf/META-INF/MANIFEST.MF
+++ b/com.google.eclipse.protobuf/META-INF/MANIFEST.MF
@@ -1,5 +1,6 @@
 Manifest-Version: 1.0
 Bundle-ManifestVersion: 2
+Eclipse-ExtensibleAPI: true
 Bundle-Name: %Bundle-Name
 Bundle-Vendor: %Bundle-Vendor
 Bundle-Version: 1.0.0