diff --git a/framework/src/org/apache/cordova/FileUtils.java b/framework/src/org/apache/cordova/FileUtils.java
index f6db0ac7..aeca5057 100755
--- a/framework/src/org/apache/cordova/FileUtils.java
+++ b/framework/src/org/apache/cordova/FileUtils.java
@@ -949,7 +949,7 @@ public class FileUtils extends CordovaPlugin {
                             result = new PluginResult(PluginResult.Status.OK, bytes, true);
                             break;
                         default: // Base64.
-                            String contentType = dataResource.getMimeType();
+                            String contentType = FileHelper.getMimeType(filename, cordova);
                             byte[] base64 = Base64.encode(bytes, Base64.DEFAULT);
                             String s = "data:" + contentType + ";base64," + new String(base64, "US-ASCII");
                             result = new PluginResult(PluginResult.Status.OK, s);