diff --git a/app/js/lib/bin_utils.js b/app/js/lib/bin_utils.js
index ff05c653..ec36ef04 100644
--- a/app/js/lib/bin_utils.js
+++ b/app/js/lib/bin_utils.js
@@ -127,18 +127,38 @@ function dataUrlToBlob (url) {
 
 function blobConstruct (blobParts, mimeType) {
   var blob
+  var safeMimeType = blobSafeMimeType(mimeType)
   try {
-    blob = new Blob(blobParts, {type: mimeType})
+    blob = new Blob(blobParts, {type: safeMimeType})
   } catch (e) {
     var bb = new BlobBuilder
     angular.forEach(blobParts, function (blobPart) {
       bb.append(blobPart)
     })
-    blob = bb.getBlob(mimeType)
+    blob = bb.getBlob(safeMimeType)
   }
   return blob
 }
 
+function blobSafeMimeType(mimeType) {
+  if ([
+    'image/jpeg',
+    'image/png',
+    'image/gif',
+    'image/webp',
+    'image/bmp',
+    'video/mp4',
+    'video/webm',
+    'video/quicktime',
+    'audio/ogg',
+    'audio/mpeg',
+    'audio/mp4',
+  ].indexOf(mimeType) == -1) {
+    return 'application/octet-stream'
+  }
+  return mimeType
+}
+
 function bytesCmp (bytes1, bytes2) {
   var len = bytes1.length
   if (len != bytes2.length) {
diff --git a/app/js/lib/config.js b/app/js/lib/config.js
index 48b95077..8797077b 100644
--- a/app/js/lib/config.js
+++ b/app/js/lib/config.js
@@ -38,6 +38,7 @@ Config.Modes = {
   chrome_packed: window.chrome && chrome.app && chrome.app.window && true || false,
   animations: true,
   memory_only: false,
+  allow_tmpfs: location.search.indexOf('tmpfs=yeahImSureIknowWhatImDoing') > 0 || false,
   push_api: location.search.indexOf('push=1') == -1
 }
 
diff --git a/app/js/lib/ng_utils.js b/app/js/lib/ng_utils.js
index 6ac60b1c..d9a8e9cc 100755
--- a/app/js/lib/ng_utils.js
+++ b/app/js/lib/ng_utils.js
@@ -180,14 +180,15 @@ angular.module('izhukov.utils', [])
     }
 
     function getUrl (fileData, mimeType) {
+      var safeMimeType = blobSafeMimeType(mimeType)
       // console.log(dT(), 'get url', fileData, mimeType, fileData.toURL !== undefined, fileData instanceof Blob)
       if (fileData.toURL !== undefined) {
-        return fileData.toURL(mimeType)
+        return fileData.toURL(safeMimeType)
       }
       if (fileData instanceof Blob) {
         return URL.createObjectURL(fileData)
       }
-      return 'data:' + mimeType + ';base64,' + bytesToBase64(fileData)
+      return 'data:' + safeMimeType + ';base64,' + bytesToBase64(fileData)
     }
 
     function getByteArray (fileData) {
@@ -466,8 +467,8 @@ angular.module('izhukov.utils', [])
         return $q.reject()
       }
       if (!(blob instanceof Blob)) {
-        var mimeType = blob.type || 'image/jpeg'
-        var address = 'data:' + mimeType + ';base64,' + bytesToBase64(blob)
+        var safeMimeType = blobSafeMimeType(blob.type || 'image/jpeg')
+        var address = 'data:' + safeMimeType + ';base64,' + bytesToBase64(blob)
         return storagePutB64String(db, fileName, address).then(function () {
           return blob
         })
@@ -604,7 +605,7 @@ angular.module('izhukov.utils', [])
     }
 
     function isAvailable () {
-      return storageIsAvailable
+      return Config.allow_tmpfs && storageIsAvailable
     }
 
     function getFile (fileName, size) {