The growing prominence of Node.js and its package manager npm popularized the use of CommonJS modules, a specification that defines how to write modules in JavaScript, when there was no module construct in the language specification yet. With source code transformation tools such as Browserify, CommonJS modules can be compiled to a single JavaScript file and be run in the browser. This emphasizes the importance of program analysis tools that can detect security vulnerabilities in CommonJS module applications. Since the scripts produced by Browserify are not well suited for static analysis, I developed my own source code transformation tool and compare the two tools by computing the call graph accuracy for the produced scripts. The experimental results for 5 different Node.js packages show that scripts produced by my tool result in more precise call graphs and are therefore better suited for static analysis.