diff --git a/README.md b/README.md
index badb3d3..e73c278 100644
--- a/README.md
+++ b/README.md
@@ -52,7 +52,7 @@ 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 only OS supported for building libcurl.js is Linux. On Debian-based systems, you can run the following command to install all the dependencies:
+Make sure you have emscripten v3.1.6, 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 jq
 ```
diff --git a/client/tools/wisp_client.sh b/client/tools/wisp_client.sh
index 5ed5151..997d196 100755
--- a/client/tools/wisp_client.sh
+++ b/client/tools/wisp_client.sh
@@ -6,11 +6,15 @@ set -e
 
 VERSION="0.3.3"
 PREFIX=$(realpath build/wisp-js)
-TARBALL_PATH="$(realpath build/wisp-archive.tgz)"
+TARBALL_PATH="$(realpath build/wisp-archive.tar.gz)"
 TARBALL_URL=$(npm view @mercuryworkshop/wisp-js@$VERSION dist.tarball)
 
+if [ -d "$PREFIX" ]; then
+  exit
+fi
+
 rm -rf $PREFIX
 mkdir -p $PREFIX
 wget $TARBALL_URL -O $TARBALL_PATH
-tar xvf $TARBALL_PATH -C $PREFIX
+tar xf $TARBALL_PATH -C $PREFIX
 rm $TARBALL_PATH
\ No newline at end of file
diff --git a/server/wisp_server b/server/wisp_server
index f931adf..dee3e21 160000
--- a/server/wisp_server
+++ b/server/wisp_server
@@ -1 +1 @@
-Subproject commit f931adf9fea476fefffb1f0c3789cafda58d54ba
+Subproject commit dee3e21dbb0b5796b56bc0d76dc58a46db1d1dd8