protobuf-dt now requires Java 6.
diff --git a/com.google.eclipse.protobuf/META-INF/MANIFEST.MF b/com.google.eclipse.protobuf/META-INF/MANIFEST.MF
index fe9e38b..323f04d 100644
--- a/com.google.eclipse.protobuf/META-INF/MANIFEST.MF
+++ b/com.google.eclipse.protobuf/META-INF/MANIFEST.MF
@@ -19,7 +19,7 @@
  org.eclipse.core.runtime;bundle-version="3.7.0"

 Import-Package: org.apache.log4j,

  org.apache.commons.logging

-Bundle-RequiredExecutionEnvironment: J2SE-1.5

+Bundle-RequiredExecutionEnvironment: JavaSE-1.6

 Export-Package: com.google.eclipse.protobuf,

  com.google.eclipse.protobuf.conversion,

  com.google.eclipse.protobuf.grammar,