diff --git a/src/jdk.jpackage/share/native/applauncher/JvmLauncher.cpp b/src/jdk.jpackage/share/native/applauncher/JvmLauncher.cpp
index 5997b80fa5f..83f45c2cdfe 100644
--- a/src/jdk.jpackage/share/native/applauncher/JvmLauncher.cpp
+++ b/src/jdk.jpackage/share/native/applauncher/JvmLauncher.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2020, 2025, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -259,7 +259,8 @@ private:
 
     int initJvmlLauncherData(JvmlLauncherData* ptr) const {
         // Store path to JLI library just behind JvmlLauncherData header.
-        char* curPtr = reinterpret_cast<char*>(ptr + 1);
+        JvmlLauncherData dummy;
+        char* curPtr = reinterpret_cast<char*>((ptr ? ptr : &dummy) + 1);
         {
             const size_t count = sizeof(char)
                     * (jliLibPath.size() + 1 /* trailing zero */);
@@ -304,7 +305,7 @@ private:
         curPtr = copyStrings(envVarValues, ptr,
                             offsetof(JvmlLauncherData, envVarValues), curPtr);
 
-        const size_t bufferSize = curPtr - reinterpret_cast<char*>(ptr);
+        const size_t bufferSize = curPtr - reinterpret_cast<char*>(ptr ? ptr : &dummy);
         if (ptr) {
             LOG_TRACE(tstrings::any() << "Initialized " << bufferSize
                                         << " bytes at " << ptr << " address");