diff --git a/bundles/org.eclipse.e4.languages.javascript.junit/src/org/eclipse/e4/languages/javascript/junit/JavaScriptTestCase.java b/bundles/org.eclipse.e4.languages.javascript.junit/src/org/eclipse/e4/languages/javascript/junit/JavaScriptTestCase.java
index fe8cb00..97eb68b 100644
--- a/bundles/org.eclipse.e4.languages.javascript.junit/src/org/eclipse/e4/languages/javascript/junit/JavaScriptTestCase.java
+++ b/bundles/org.eclipse.e4.languages.javascript.junit/src/org/eclipse/e4/languages/javascript/junit/JavaScriptTestCase.java
@@ -41,6 +41,7 @@
 	private ClassLoader applicationClassLoader;
 	private ClassLoader originalApplicationClassLoader;
 	private boolean superRunTest = false;
+	private volatile static int evalCount;
 	private static URL ASSERT_SCRIPT = JavaScriptTestCase.class.getResource("assert.js");
 	
 	static {
@@ -145,7 +146,7 @@
 
 	public Object eval(String source, String sourceName) {
 		if (sourceName == null) {
-			sourceName = "eval";
+			sourceName = "eval-" + evalCount++;
 		}
 		return context.evaluateString(globalScope, source, sourceName, 1, null);
 	}