diff --git a/overviewer_core/observer.py b/overviewer_core/observer.py
index 63c5a7a..9db9baf 100644
--- a/overviewer_core/observer.py
+++ b/overviewer_core/observer.py
@@ -256,11 +256,10 @@ class JSObserver(Observer):
             raise Exception("JSObserver: messages parameter must be a "
                             "dictionary with three entries: totalTiles, "
                             "renderCompleted and renderProgress")
+        # On the initial render, the outputdir hasn't been created until after the observer is
+        # initialised, so let's just do it here if necessary.
         if not os.path.exists(outputdir):
-            raise Exception("JSObserver: Output directory specified (%s) "
-                            "doesn't appear to exist. This should be the "
-                            "same as the Overviewer output directory"
-                            % outputdir)
+            os.mkdir(outputdir)
 
         self.logfile = open(os.path.join(outputdir, "progress.json"), "wb+", 0)
         self.json["message"] = "Render starting..."