WebAssembly is quickly becoming a popular compilation target for a variety of code. However, vulnerabilities in the source languages translate to vulnerabilities in the WebAssembly binaries. This work proposes a methodology and a WebAssembly transpiler to prevent buffer overflows in the unmanaged memory of the WebAssembly runtime. The transpiler accepts a WebAssembly binary and adds stack canaries and Address Space Layout Randomization (ASLR) to protect against buffer overflows.