singleton directive required!?

tests/org.eclipse.wst.html.core.tests/META-INF/MANIFEST.MF

diff --git a/tests/org.eclipse.wst.html.core.tests/META-INF/MANIFEST.MF b/tests/org.eclipse.wst.html.core.tests/META-INF/MANIFEST.MF
index 25b8318..bc8ea4c 100644
--- a/tests/org.eclipse.wst.html.core.tests/META-INF/MANIFEST.MF
+++ b/tests/org.eclipse.wst.html.core.tests/META-INF/MANIFEST.MF
@@ -1,7 +1,7 @@
 Manifest-Version: 1.0
 Bundle-ManifestVersion: 2
 Bundle-Name: %Bundle-Name.0
-Bundle-SymbolicName: org.eclipse.wst.html.core.tests
+Bundle-SymbolicName: org.eclipse.wst.html.core.tests;singleton:=true
 Bundle-Version: 1.0.101.qualifier
 Bundle-ClassPath: htmlcoretests.jar
 Bundle-Activator: org.eclipse.wst.html.core.tests.HTMLCoreTestsPlugin