diff --git a/releng/org.eclipse.cdt.sdk/META-INF/MANIFEST.MF b/releng/org.eclipse.cdt.sdk/META-INF/MANIFEST.MF
index f83d7f49add..4f7b0178483 100644
--- a/releng/org.eclipse.cdt.sdk/META-INF/MANIFEST.MF
+++ b/releng/org.eclipse.cdt.sdk/META-INF/MANIFEST.MF
@@ -1,7 +1,7 @@
 Manifest-Version: 1.0
 Bundle-ManifestVersion: 2
 Bundle-Name: %pluginName
-Bundle-SymbolicName: org.eclipse.cdt.sdk
+Bundle-SymbolicName: org.eclipse.cdt.sdk;singleton:=true
 Bundle-Version: 5.0.0.qualifier
 Bundle-Vendor: %providerName
 Bundle-Localization: plugin
diff --git a/releng/org.eclipse.cdt.testing/META-INF/MANIFEST.MF b/releng/org.eclipse.cdt.testing/META-INF/MANIFEST.MF
index 321c3a82512..c651f7de8d7 100644
--- a/releng/org.eclipse.cdt.testing/META-INF/MANIFEST.MF
+++ b/releng/org.eclipse.cdt.testing/META-INF/MANIFEST.MF
@@ -1,7 +1,7 @@
 Manifest-Version: 1.0
 Bundle-ManifestVersion: 2
 Bundle-Name: %pluginName
-Bundle-SymbolicName: org.eclipse.cdt.testing
+Bundle-SymbolicName: org.eclipse.cdt.testing;singleton:=true
 Bundle-Version: 5.0.0.qualifier
 Bundle-Vendor: %providerName
 Bundle-Localization: plugin