diff --git a/independent-projects/bootstrap/runner/src/main/java/io/quarkus/bootstrap/runner/SerializedApplication.java b/independent-projects/bootstrap/runner/src/main/java/io/quarkus/bootstrap/runner/SerializedApplication.java
index a1f6c2201fa58..97c29b116a536 100644
--- a/independent-projects/bootstrap/runner/src/main/java/io/quarkus/bootstrap/runner/SerializedApplication.java
+++ b/independent-projects/bootstrap/runner/src/main/java/io/quarkus/bootstrap/runner/SerializedApplication.java
@@ -57,7 +57,7 @@ public static void write(OutputStream outputStream, String mainClass, Path appli
             data.writeUTF(mainClass);
             data.writeInt(classPath.size());
             for (Path jar : classPath) {
-                String relativePath = relativize(applicationRoot, jar).replace("\\", "/");
+                String relativePath = applicationRoot.relativize(jar).toString().replace("\\", "/");
                 data.writeUTF(relativePath);
                 writeJar(data, jar);
             }
@@ -226,12 +226,4 @@ private static void writeNullableString(DataOutputStream out, String string) thr
         }
     }
 
-    private static String relativize(Path applicationRoot, Path jar) {
-        Path relative = applicationRoot.relativize(jar);
-        if (relative.getName(0).toString().equals("..")) {
-            throw new RuntimeException(jar + " was not present in application " + applicationRoot);
-        }
-        return relative.toString();
-    }
-
 }
diff --git a/integration-tests/maven/src/test/java/io/quarkus/maven/it/JarRunnerIT.java b/integration-tests/maven/src/test/java/io/quarkus/maven/it/JarRunnerIT.java
index fb762ac153ec2..e7d02ccfb60ae 100644
--- a/integration-tests/maven/src/test/java/io/quarkus/maven/it/JarRunnerIT.java
+++ b/integration-tests/maven/src/test/java/io/quarkus/maven/it/JarRunnerIT.java
@@ -93,12 +93,22 @@ public void testThatFastJarCustomOutputDirFormatWorks() throws Exception {
 
     @Test
     public void testThatMutableFastJarWorks() throws Exception {
-        File testDir = initProject("projects/classic", "projects/project-classic-console-output-mutable-fast-jar");
+        assertThatMutableFastJarWorks("providers", "providers");
+    }
+
+    @Test
+    public void testThatMutableFastJarWorksProvidersDirOutsideOutputDir() throws Exception {
+        assertThatMutableFastJarWorks("outsidedir", ".." + File.separator + "providers");
+    }
+
+    private void assertThatMutableFastJarWorks(String targetDirSuffix, String providersDir) throws Exception {
+        File testDir = initProject("projects/classic",
+                "projects/project-classic-console-output-mutable-fast-jar" + targetDirSuffix);
         RunningInvoker running = new RunningInvoker(testDir, false);
 
         MavenProcessInvocationResult result = running
                 .execute(Arrays.asList("package", "-DskipTests", "-Dquarkus.package.type=mutable-jar",
-                        "-Dquarkus.package.user-providers-directory=providers"), Collections.emptyMap());
+                        "-Dquarkus.package.user-providers-directory=" + providersDir), Collections.emptyMap());
 
         await().atMost(1, TimeUnit.MINUTES).until(() -> result.getProcess() != null && !result.getProcess().isAlive());
         assertThat(running.log()).containsIgnoringCase("BUILD SUCCESS");
@@ -113,7 +123,7 @@ public void testThatMutableFastJarWorks() throws Exception {
         Assertions.assertTrue(Files.exists(jar));
 
         Path providers = testDir.toPath().toAbsolutePath()
-                .resolve(Paths.get("target/quarkus-app/providers"));
+                .resolve(Paths.get("target/quarkus-app/" + providersDir));
         Assertions.assertTrue(Files.exists(providers));
 
         File output = new File(testDir, "target/output.log");