diff --git a/test-framework/junit5/src/main/java/io/quarkus/test/junit/QuarkusTestExtension.java b/test-framework/junit5/src/main/java/io/quarkus/test/junit/QuarkusTestExtension.java
index 0d2f2491eebd14..96ef48355efe3f 100644
--- a/test-framework/junit5/src/main/java/io/quarkus/test/junit/QuarkusTestExtension.java
+++ b/test-framework/junit5/src/main/java/io/quarkus/test/junit/QuarkusTestExtension.java
@@ -9,6 +9,7 @@
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
+import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -106,7 +107,7 @@ private ExtensionState doJavaStart(ExtensionContext context) throws Throwable {
             }
             CuratedApplication curatedApplication = runnerBuilder
                     .setTest(true)
-                    .setProjectRoot(new File("").toPath())
+                    .setProjectRoot(Files.isDirectory(appClassLocation) ? new File("").toPath() : null)
                     .build()
                     .bootstrap();