diff --git a/test-support/src/main/java/org/eclipse/gemini/blueprint/test/internal/util/jar/JarCreator.java b/test-support/src/main/java/org/eclipse/gemini/blueprint/test/internal/util/jar/JarCreator.java
index 27f0bdb..29cbb11 100644
--- a/test-support/src/main/java/org/eclipse/gemini/blueprint/test/internal/util/jar/JarCreator.java
+++ b/test-support/src/main/java/org/eclipse/gemini/blueprint/test/internal/util/jar/JarCreator.java
@@ -134,7 +134,7 @@
 	 */
 	private String determineRelativeName(String rootPath, Resource resource) {
 		try {
-			String path = StringUtils.cleanPath(resource.getURL().toExternalForm());
+			String path = StringUtils.cleanPath(resource.getURL().getPath());
 			return path.substring(path.indexOf(rootPath) + rootPath.length());
 		}
 		catch (IOException ex) {