diff --git a/android/app/src/main/cpp/androidapp.cpp b/android/app/src/main/cpp/androidapp.cpp
index 97000797aa..89a703ceb4 100644
--- a/android/app/src/main/cpp/androidapp.cpp
+++ b/android/app/src/main/cpp/androidapp.cpp
@@ -64,14 +64,14 @@ static void send2JS(jclass mainActivityClz, jobject mainActivityObj, const std::
     {
         // The data needs to be an ArrayBuffer
         std::stringstream ss;
-        ss << "{'base64data':'";
+        ss << "Base64ToArrayBuffer('";
 
         Poco::Base64Encoder encoder(ss);
         encoder.rdbuf()->setLineLength(0); // unlimited
         encoder << std::string(buffer.data(), buffer.size());
         encoder.close();
 
-        ss << "'}";
+        ss << "')";
 
         js = ss.str();
     }
@@ -93,8 +93,9 @@ static void send2JS(jclass mainActivityClz, jobject mainActivityObj, const std::
                 data.push_back(ubufp[i]);
             }
         }
+        data.push_back(0);
 
-        js = "{'data':'" + std::string(data.data(), data.size()) + "'}";
+        js = std::string(data.data(), data.size());
     }
 
     std::string subjs = js.substr(0, std::min(std::string::size_type(SHOW_JS_MAXLEN), js.length()));
diff --git a/android/app/src/main/java/org/libreoffice/androidapp/MainActivity.java b/android/app/src/main/java/org/libreoffice/androidapp/MainActivity.java
index 88601d0beb..564df1911d 100644
--- a/android/app/src/main/java/org/libreoffice/androidapp/MainActivity.java
+++ b/android/app/src/main/java/org/libreoffice/androidapp/MainActivity.java
@@ -181,7 +181,7 @@ public class MainActivity extends AppCompatActivity {
         mWebView.post(new Runnable() {
             public void run() {
                 Log.i(TAG,"Forwarding to the WebView: " + message);
-                mWebView.loadUrl("javascript:window.TheFakeWebSocket.onmessage(" + message + ");");
+                mWebView.loadUrl("javascript:window.TheFakeWebSocket.onmessage({'data': '" + message + "'});");
             }
         });
     }
diff --git a/gtk/mobile.cpp b/gtk/mobile.cpp
index b2c346f7c2..929e07d17c 100644
--- a/gtk/mobile.cpp
+++ b/gtk/mobile.cpp
@@ -58,11 +58,11 @@ static void send2JS(const std::vector<char>& buffer)
     if (newline != nullptr)
     {
         // The data needs to be an ArrayBuffer
-        js = "window.TheFakeWebSocket.onmessage({'base64data':'";
+        js = "window.TheFakeWebSocket.onmessage({'data': Base64ToArrayBuffer('";
         gchar *base64 = g_base64_encode((const guchar*)buffer.data(), buffer.size());
         js = js + std::string(base64);
         g_free(base64);
-        js = js + "'});";
+        js = js + "')});";
     }
     else
     {
@@ -84,7 +84,7 @@ static void send2JS(const std::vector<char>& buffer)
         }
         data.push_back(0);
 
-        js = "window.TheFakeWebSocket.onmessage({'data':'";
+        js = "window.TheFakeWebSocket.onmessage({'data': '";
         js = js + std::string(buffer.data(), buffer.size());
         js = js + "'});";
     }
diff --git a/ios/Mobile/Document.mm b/ios/Mobile/Document.mm
index 804ba65d25..70d130d64c 100644
--- a/ios/Mobile/Document.mm
+++ b/ios/Mobile/Document.mm
@@ -82,9 +82,9 @@
     const char *newline = (const char *)memchr(buffer, '\n', length);
     if (newline != nullptr) {
         // The data needs to be an ArrayBuffer
-        js = @"window.TheFakeWebSocket.onmessage({'base64data':'";
+        js = @"window.TheFakeWebSocket.onmessage({'data': Base64ToArrayBuffer('";
         js = [js stringByAppendingString: [[NSData dataWithBytes:buffer length:length] base64EncodedStringWithOptions:0]];
-        js = [js stringByAppendingString:@"'});"];
+        js = [js stringByAppendingString:@"')});"];
         NSString *subjs = [js substringToIndex:std::min(100ul, js.length)];
         if (subjs.length < js.length)
             subjs = [subjs stringByAppendingString:@"..."];
@@ -116,7 +116,7 @@
         }
         data.push_back(0);
 
-        js = @"window.TheFakeWebSocket.onmessage({'data':'";
+        js = @"window.TheFakeWebSocket.onmessage({'data': '";
         js = [js stringByAppendingString:[NSString stringWithUTF8String:data.data()]];
         js = [js stringByAppendingString:@"'});"];
 
diff --git a/loleaflet/html/loleaflet.html.m4 b/loleaflet/html/loleaflet.html.m4
index a8233ba82b..f43dd488f2 100644
--- a/loleaflet/html/loleaflet.html.m4
+++ b/loleaflet/html/loleaflet.html.m4
@@ -12,7 +12,7 @@ define([_foreachq],[ifelse([$#],[3],[],[define([$1],[$4])$2[]$0([$1],[$2],shift(
 <meta name="viewport" content="width=device-width, initial-scale=1.0">
 
 <script>
-dnl# Define MOBILEAPP as true if this is either for the iOS app, Android app or for the gtk+ "app" testbed
+dnl# Define MOBILEAPP as true if this is either for the iOS app or for the gtk+ "app" testbed
 define([MOBILEAPP],[])
 ifelse(IOSAPP,[true],[define([MOBILEAPP],[true])])
 ifelse(GTKAPP,[true],[define([MOBILEAPP],[true])])
@@ -31,6 +31,16 @@ ifelse(MOBILEAPP,[],
   };
   window.addEventListener('message', PostMessageReadyListener, false);
 )dnl
+
+var Base64ToArrayBuffer = function(base64Str) {
+  var binStr = atob(base64Str);
+  var ab = new ArrayBuffer(binStr.length);
+  var bv = new Uint8Array(ab);
+  for (var i = 0, l = binStr.length; i < l; i++) {
+    bv[[i]] = binStr.charCodeAt(i);
+  }
+  return ab;
+}
 </script>
 
 ifelse(MOBILEAPP,[true],
diff --git a/loleaflet/src/core/Socket.js b/loleaflet/src/core/Socket.js
index 649dcddfd2..19c49ddef2 100644
--- a/loleaflet/src/core/Socket.js
+++ b/loleaflet/src/core/Socket.js
@@ -241,10 +241,7 @@ L.Socket = L.Class.extend({
 	_onMessage: function (e) {
 		var imgBytes, index, textMsg;
 
-		if (typeof(e.base64data) === 'string') {
-			textMsg = atob(e.base64data);
-		}
-		else if (typeof (e.data) === 'string') {
+		if (typeof (e.data) === 'string') {
 			textMsg = e.data;
 		}
 		else if (typeof (e.data) === 'object') {