diff --git a/compiler/core/src/zserio/tools/ExtensionManager.java b/compiler/core/src/zserio/tools/ExtensionManager.java
index 9188cac25..6137576ba 100644
--- a/compiler/core/src/zserio/tools/ExtensionManager.java
+++ b/compiler/core/src/zserio/tools/ExtensionManager.java
@@ -123,12 +123,12 @@ private ClassLoader getClassLoader()
                 System.out.println("Found file: " + file);
                 if (isFileZserioExtension(file))
                 {
-                    urlArray.add(new URI("jar:file:" + file.getPath() + "!/").toURL());
+                    urlArray.add(new URL("jar:file:" + file.getPath() + "!/"));
                     urlArray.addAll(getDependentJarsFromManifest(file));
                 }
             }
         }
-        catch (MalformedURLException | URISyntaxException excpt)
+        catch (MalformedURLException excpt)
         {
             System.out.println("Exception!");
             return currentClassLoader;