diff --git a/codecs/cpp.Dockerfile b/codecs/cpp.Dockerfile
index 88e489db..ea1507ae 100644
--- a/codecs/cpp.Dockerfile
+++ b/codecs/cpp.Dockerfile
@@ -5,5 +5,7 @@ ENV CXXFLAGS "${CFLAGS} -std=c++17"
 ENV LDFLAGS "${CFLAGS}"
 # Build and cache standard libraries with these flags
 RUN emcc ${CXXFLAGS} --bind -xc++ /dev/null -o /dev/null
+RUN curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.35.3/install.sh | bash
+RUN /bin/bash -ic 'nvm install 14.7.0'
 WORKDIR /src
 CMD ["sh", "-c", "emmake make -j`nproc`"]
diff --git a/codecs/mozjpeg_enc/.emscripten b/codecs/mozjpeg_enc/.emscripten
new file mode 100644
index 00000000..5da1fd50
--- /dev/null
+++ b/codecs/mozjpeg_enc/.emscripten
@@ -0,0 +1,13 @@
+import os
+emsdk_path = "/emsdk/"
+#NODE_JS = emsdk_path + '/node/12.18.1_64bit/bin/node'
+# We need a newer version of Node that supports the most recent iteration of Wasm SIMD
+# and need to enable that experimental support via flag so that autoconf can successfully
+# detect SIMD support.
+NODE_JS=["/root/.nvm/versions/node/v14.7.0/bin/node", "--experimental-wasm-simd"]
+LLVM_ROOT = emsdk_path + '/upstream/bin'
+BINARYEN_ROOT = emsdk_path + '/upstream'
+EMSCRIPTEN_ROOT = emsdk_path + '/upstream/emscripten'
+TEMP_DIR = emsdk_path + '/tmp'
+COMPILER_ENGINE = NODE_JS
+JS_ENGINES = [NODE_JS]
diff --git a/codecs/mozjpeg_enc/Makefile b/codecs/mozjpeg_enc/Makefile
index 30b5ca0e..542e0b78 100644
--- a/codecs/mozjpeg_enc/Makefile
+++ b/codecs/mozjpeg_enc/Makefile
@@ -5,11 +5,21 @@ CODEC_OUT := $(addprefix $(CODEC_DIR)/, $(CODEC_OUT_RELATIVE))
 OUT_JS := mozjpeg_enc.js
 OUT_WASM := $(OUT_JS:.js=.wasm)
 
+CFLAGS += -msimd128 -msse --em-config /src/.emscripten
+CXXFLAGS += -msimd128 -msse --em-config /src/.emscripten
+
+#override CFLAGS += "-msimd128 -msse"
+#override CXXFLAGS += "-msimd128 -msse"
+
 .PHONY: all clean
 
 all: $(OUT_JS)
 
 %.js: %.cpp $(CODEC_OUT)
+	# We just to disable the overridden NODE_JS binary because 
+	# `--closure 1` can’t handle arrays in `.emscripten` it seems.
+	# https://github.com/emscripten-core/emsdk/issues/583
+	export EM_NODE_JS='/root/.nvm/versions/node/v14.7.0/bin/node' && \
 	$(CXX) \
 		-I $(CODEC_DIR) \
 		${CXXFLAGS} \
diff --git a/codecs/mozjpeg_enc/example.html b/codecs/mozjpeg_enc/example.html
index 2cff900f..76b54ef1 100644
--- a/codecs/mozjpeg_enc/example.html
+++ b/codecs/mozjpeg_enc/example.html
@@ -1,26 +1,14 @@
 <!doctype html>
 <script src='mozjpeg_enc.js'></script>
 <script>
-  const module = mozjpeg_enc();
-
-  async function loadImage(src) {
-    // Load image
-    const img = document.createElement('img');
-    img.src = src;
-    await new Promise(resolve => img.onload = resolve);
-    // Make canvas same size as image
-    const canvas = document.createElement('canvas');
-    [canvas.width, canvas.height] = [img.width, img.height];
-    // Draw image onto canvas
-    const ctx = canvas.getContext('2d');
-    ctx.drawImage(img, 0, 0);
-    return ctx.getImageData(0, 0, img.width, img.height);
-  }
-
-  module.onRuntimeInitialized = async _ => {
-    console.log('Version:', module.version().toString(16));
+	const module = mozjpeg_enc({
+	loadFile() {
+		return "./mozjpeg_enc.wasm";
+	},
+  async onRuntimeInitialized() {
+    //console.log('Version:', module.version().toString(16));
     const image = await loadImage('../example.png');
-    const result = module.encode(image.data, image.width, image.height, {
+    const result = this.encode(image.data, image.width, image.height, {
       quality: 75,
       baseline: false,
       arithmetic: false,
@@ -44,5 +32,21 @@
     const img = document.createElement('img');
     img.src = blobURL;
     document.body.appendChild(img);
-  };
+  }
+	});
+
+  async function loadImage(src) {
+    // Load image
+    const img = document.createElement('img');
+    img.src = src;
+    await new Promise(resolve => img.onload = resolve);
+    // Make canvas same size as image
+    const canvas = document.createElement('canvas');
+    [canvas.width, canvas.height] = [img.width, img.height];
+    // Draw image onto canvas
+    const ctx = canvas.getContext('2d');
+    ctx.drawImage(img, 0, 0);
+    return ctx.getImageData(0, 0, img.width, img.height);
+  }
+
 </script>
diff --git a/codecs/mozjpeg_enc/mozjpeg_enc.cpp b/codecs/mozjpeg_enc/mozjpeg_enc.cpp
index 27388587..3673db5c 100644
--- a/codecs/mozjpeg_enc/mozjpeg_enc.cpp
+++ b/codecs/mozjpeg_enc/mozjpeg_enc.cpp
@@ -1,5 +1,7 @@
 #include <emscripten/bind.h>
 #include <emscripten/val.h>
+#include <wasm_simd128.h>
+#include <xmmintrin.h>
 #include <inttypes.h>
 #include <setjmp.h>
 #include <stdio.h>
diff --git a/codecs/mozjpeg_enc/mozjpeg_enc.wasm b/codecs/mozjpeg_enc/mozjpeg_enc.wasm
index bf5df729..e6e508c2 100644
Binary files a/codecs/mozjpeg_enc/mozjpeg_enc.wasm and b/codecs/mozjpeg_enc/mozjpeg_enc.wasm differ
