diff --git a/README.md b/README.md
index ac9c981..f26369b 100644
--- a/README.md
+++ b/README.md
@@ -18,12 +18,16 @@ git clone https://github.com/ading2210/libcurl.js --recursive
 cd libcurl.js/client
 ./build.sh
 ```
-Make sure you have emscripten, git, and the various C build tools installed. The build script will generate `client/out/libcurl.js` as well as `client/out/libcurl_module.mjs`, which is an ES6 module.
+Make sure you have emscripten, git, and the various C build tools installed. The only OS supported for building libcurl.js is Linux. On Debian-based systems, you can run the following command to install all the dependencies:
+```
+sudo apt install make cmake emscripten autoconf automake libtool pkg-config wget xxd
+```
 
-You can supply the following arguments to the build script to control the build:
+The build script will generate `client/out/libcurl.js` as well as `client/out/libcurl_module.mjs`, which is an ES6 module. You can supply the following arguments to the build script to control the build:
 - `release` - Use all optimizations.
 - `single_file` - Include the WASM binary in the outputted JS using base64.
 
+
 ## Javascript API:
 
 ### Importing the Library:
diff --git a/client/javascript/main.js b/client/javascript/main.js
index 00fa80c..851fbdf 100644
--- a/client/javascript/main.js
+++ b/client/javascript/main.js
@@ -1,6 +1,10 @@
 //everything is wrapped in a function to prevent emscripten from polluting the global scope
 window.libcurl = (function() {
 
+if (typeof window === "undefined") {
+  throw new Error("NodeJS is not supported. This only works inside the browser.");
+}
+
 //emscripten compiled code is inserted here
 /* __emscripten_output__ */
 
diff --git a/client/tools/all_deps.sh b/client/tools/all_deps.sh
index 13bd32e..d3b857c 100755
--- a/client/tools/all_deps.sh
+++ b/client/tools/all_deps.sh
@@ -2,6 +2,7 @@
 
 #build all deps
 
+set -e
 mkdir -p build
 
 OPENSSL_PREFIX=$(realpath build/openssl-wasm)