synchronized for getSources()
diff --git a/plugins/org.eclipse.dltk.ruby.launching/src/org/eclipse/dltk/ruby/internal/launching/RubyGenericInstall.java b/plugins/org.eclipse.dltk.ruby.launching/src/org/eclipse/dltk/ruby/internal/launching/RubyGenericInstall.java
index 98aff77..d10ef36 100644
--- a/plugins/org.eclipse.dltk.ruby.launching/src/org/eclipse/dltk/ruby/internal/launching/RubyGenericInstall.java
+++ b/plugins/org.eclipse.dltk.ruby.launching/src/org/eclipse/dltk/ruby/internal/launching/RubyGenericInstall.java
@@ -125,7 +125,7 @@
 			}
 		}
 
-		public Map getSources() {
+		public synchronized Map getSources() {
 			if (sources == null) {
 				sources = new HashMap();