diff --git a/README.md b/README.md
index a270ac6b3..366e504a9 100644
--- a/README.md
+++ b/README.md
@@ -47,6 +47,28 @@ make USERNAME="{Your name, max 15 characters}" -j4
 make epsilon_flash
 ```
 
+* Building the **web simulator** (works under linux):
+
+First, install emsdk :
+```
+git clone https://github.com/emscripten-core/emsdk.git
+cd emsdk
+./emsdk install latest-fastcomp
+./emsdk activate latest-fastcomp
+source emsdk_env.sh
+```
+
+Then, compile Omega :
+```
+git clone --recursive https://github.com/Omega-Numworks/Omega.git
+cd Omega
+make clean
+make PLATFORM=simulator TARGET=web USERNAME="{Your name, max 15 characters}" -j4
+```
+
+The simulator is now in `output/release/simulator/web/simulator.zip`
+
+
 Important: Don't forget the `--recursive` tag, because Omega relies on submodules.
 Also, you can change the number of processes that run in parallel during the build by changing the value of the `-j` flag.
 <!-- ## Contribute -->
diff --git a/build/toolchain.emscripten.mak b/build/toolchain.emscripten.mak
index 9ac1010a2..b2fa4b714 100644
--- a/build/toolchain.emscripten.mak
+++ b/build/toolchain.emscripten.mak
@@ -8,6 +8,8 @@ SAFE_HEAP_STORE \
 _IonEventsEmscriptenKeyDown \
 _IonEventsEmscriptenKeyUp \
 _IonEventsEmscriptenPushEvent \
+_IonSimulatorCallbackDidScanKeyboard \
+__Z8ion_mainiPKPKc \
 __Z8ion_mainiPPc \
 __ZN10Invocation7performEPv \
 __ZN11MicroPython20ExecutionEnvironment7runCodeEPKc \
@@ -108,8 +110,11 @@ EMFLAGS += --profiling-funcs
 EMFLAGS += -s ASSERTIONS=1
 EMFLAGS += -s SAFE_HEAP=1
 EMFLAGS += -s STACK_OVERFLOW_CHECK=1
+EMFLAGS += -s DEMANGLE_SUPPORT=1
 endif
 
+# EMFLAGS += -s ERROR_ON_UNDEFINED_SYMBOLS=0
+
 # Configure EMFLAGS
 EMFLAGS += -s WASM=0
 
@@ -120,4 +125,4 @@ EMSCRIPTEN_INIT_FILE ?= 0
 LDFLAGS += --memory-init-file $(EMSCRIPTEN_INIT_FILE)
 
 SFLAGS += $(EMFLAGS)
-LDFLAGS += $(EMFLAGS) -Oz -s EXPORTED_FUNCTIONS='["_main", "_IonSimulatorKeyboardKeyDown", "_IonSimulatorKeyboardKeyUp", "_IonSimulatorEventsPushEvent", "_IonSoftwareVersion", "_IonPatchLevel"]' -s EXTRA_EXPORTED_RUNTIME_METHODS='["UTF8ToString"]'
+LDFLAGS += $(EMFLAGS) -Oz -s EXPORTED_FUNCTIONS='["_main", "_IonSimulatorKeyboardKeyDown", "_IonSimulatorKeyboardKeyUp", "_IonSimulatorEventsPushEvent", "_IonSoftwareVersion", "_IonPatchLevel"]' -s EXTRA_EXPORTED_RUNTIME_METHODS='["UTF8ToString", "Pointer_stringify"]'
diff --git a/ion/src/simulator/shared/main_sdl.cpp b/ion/src/simulator/shared/main_sdl.cpp
index d4aca04c3..06652578c 100644
--- a/ion/src/simulator/shared/main_sdl.cpp
+++ b/ion/src/simulator/shared/main_sdl.cpp
@@ -122,9 +122,12 @@ void init() {
 
   Display::init(sRenderer);
 
+  // No need to load background in web simulator.
+  #ifndef __EMSCRIPTEN__
   if (!argument_screen_only) {
     sBackgroundTexture = IonSimulatorLoadImage(sRenderer, "background.jpg");
   }
+  #endif
 
   relayout();
 }
diff --git a/ion/src/simulator/web/simulator.html b/ion/src/simulator/web/simulator.html
index 5de5de636..d733dac5e 100644
--- a/ion/src/simulator/web/simulator.html
+++ b/ion/src/simulator/web/simulator.html
@@ -298,6 +298,6 @@ window.addEventListener("keydown", function(e) {
   }
 }, false);
     </script>
-    <script async src="https://www.numworks.com/simulator/update.js"></script>
+    <!--<script async src="https://www.numworks.com/simulator/update.js"></script>-->
   </body>
 </html>