diff --git a/MarkdownLivePreview.py b/MarkdownLivePreview.py
index b285727..c9c9fa8 100644
--- a/MarkdownLivePreview.py
+++ b/MarkdownLivePreview.py
@@ -169,11 +169,6 @@ class MarkdownLivePreviewListener(sublime_plugin.EventListener):
         if not infos:
             return
 
-        self.debug_message(
-            "on_close: view_id: %d, close_id: %d" % (markdown_view.id(), view.id())
-        )
-        assert markdown_view.id() == view.id(), "pre_close view.id() != close view.id()"
-
         if markdown_view.id() in self.phantom_sets:
             del self.phantom_sets[markdown_view.id()]
 
diff --git a/markdown2html.py b/markdown2html.py
index 09df2db..742b9c3 100644
--- a/markdown2html.py
+++ b/markdown2html.py
@@ -107,7 +107,7 @@ def markdown2html(markdown, basepath, re_render, resources, viewport_width, font
             target_size = round(BASE_PX_SIZE * multiplier * font_scale)
             # Simple style setting (overwrites existing inline style if any)
             # A more robust solution would parse and merge existing styles
-            element['style'] = f"font-size: {target_size}px;"
+            element['style'] = "font-size: {}px;".format(target_size)
 
     # FIXME: report that ST doesn't support <br/> but does work with <br />... WTF?
     stylesheet = resources["stylesheet"] # Use only the base stylesheet