diff --git a/src/pyj/read_book/comm.pyj b/src/pyj/iframe_comm.pyj
similarity index 96%
rename from src/pyj/read_book/comm.pyj
rename to src/pyj/iframe_comm.pyj
index 35372ae844..9e1e497b5b 100644
--- a/src/pyj/read_book/comm.pyj
+++ b/src/pyj/iframe_comm.pyj
@@ -18,7 +18,7 @@ LOADING_DOC = '''
 <meta name="viewport" content="width=device-width, initial-scale=1, user-scalable=no">
 <meta http-equiv="X-UA-Compatible" content="IE=edge">
 <script type="text/javascript" id="bootstrap">
-window.iframe_type = '__IFRAME_TYPE__';  // different in different iframes
+window.iframe_entry_point = '__ENTRY_POINT__';  // different in different iframes
 window.default_font_family = '__FONT__';  // from the theme
 __SCRIPT__
 end_script
@@ -58,14 +58,14 @@ class Messenger:
 
 class IframeWrapper:
 
-    def __init__(self, handlers, iframe, iframe_type, bootstrap_text):
+    def __init__(self, handlers, iframe, entry_point, bootstrap_text):
         self.messenger = Messenger()
         self.iframe_id = ensure_id(iframe, 'content-iframe')
         self.needs_init = True
         self.ready = False
         self.encrypted_communications = False
         self.srcdoc_created = False
-        self.iframe_type = iframe_type
+        self.entry_point = entry_point
         self.bootstrap_text = bootstrap_text
         self.handlers = {k: handlers[k] for k in handlers}
         self.on_ready_handler = self.handlers.ready
@@ -82,7 +82,7 @@ class IframeWrapper:
             'BS': self.bootstrap_text,
             'SCRIPT': iframe_js(),
             'FONT': get_font_family(),
-            'IFRAME_TYPE': self.iframe_type,
+            'ENTRY_POINT': self.entry_point,
         }
         self.iframe.srcdoc = LOADING_DOC.replace(r, def(match, field): return data[field];)
         self.srcdoc_created = True
diff --git a/src/pyj/read_book/content_popup.pyj b/src/pyj/read_book/content_popup.pyj
index 2c356f0d04..32b70d7e5d 100644
--- a/src/pyj/read_book/content_popup.pyj
+++ b/src/pyj/read_book/content_popup.pyj
@@ -6,7 +6,7 @@ from elementmaker import E
 from gettext import gettext as _
 
 from dom import add_extra_css, build_rule, clear, svgicon
-from read_book.comm import IframeWrapper
+from iframe_comm import IframeWrapper
 from read_book.resources import load_resources
 
 CLASS_NAME = 'book-content-popup-container'
@@ -56,7 +56,7 @@ class ContentPopupOverlay:
             'error': self.view.on_iframe_error,
             'content_loaded': self.on_content_loaded,
         }
-        self.iframe_wrapper = IframeWrapper(handlers, iframe, 'popup', _('Loading data, please wait...'))
+        self.iframe_wrapper = IframeWrapper(handlers, iframe, 'read_book.footnotes', _('Loading data, please wait...'))
         self.pending_load = None
 
     @property
diff --git a/src/pyj/read_book/footnotes.pyj b/src/pyj/read_book/footnotes.pyj
index 6d5c726cb3..cfff5b7362 100644
--- a/src/pyj/read_book/footnotes.pyj
+++ b/src/pyj/read_book/footnotes.pyj
@@ -3,7 +3,7 @@
 from __python__ import bound_methods, hash_literals
 
 from dom import clear
-from read_book.comm import IframeClient
+from iframe_comm import IframeClient
 from read_book.resources import finalize_resources, unserialize_html
 from read_book.settings import apply_settings, update_settings
 
@@ -220,3 +220,7 @@ class PopupIframeBoss:
     def content_loaded(self):
         apply_settings()
         self.comm.send_message('content_loaded', height=document.documentElement.scrollHeight + 25)
+
+
+def main():
+    main.boss = PopupIframeBoss()
diff --git a/src/pyj/read_book/iframe.pyj b/src/pyj/read_book/iframe.pyj
index 93f05d6604..78958d2877 100644
--- a/src/pyj/read_book/iframe.pyj
+++ b/src/pyj/read_book/iframe.pyj
@@ -5,14 +5,14 @@ from __python__ import bound_methods, hash_literals
 import traceback
 from gettext import gettext as _
 
+from iframe_comm import IframeClient
 from read_book.cfi import at_current, scroll_to as scroll_to_cfi
-from read_book.comm import IframeClient
 from read_book.flow_mode import (
     anchor_funcs as flow_anchor_funcs, flow_onkeydown, flow_onwheel,
     flow_to_scroll_fraction, handle_gesture as flow_handle_gesture,
     layout as flow_layout, scroll_by_page as flow_scroll_by_page
 )
-from read_book.footnotes import PopupIframeBoss, is_footnote_link
+from read_book.footnotes import is_footnote_link
 from read_book.globals import (
     current_book, current_layout_mode, current_spine_item, set_boss,
     set_current_spine_item, set_layout_mode
@@ -382,10 +382,6 @@ class IframeBoss:
             else:
                 self.send_message('find_in_spine', text=data.text, backwards=data.backwards, searched_in_spine=data.searched_in_spine)
 
-def init():
-    if window.iframe_type is 'main':
-        script = document.getElementById('bootstrap')
-        script.parentNode.removeChild(script)  # free up some memory
-        IframeBoss()
-    elif window.iframe_type is 'popup':
-        PopupIframeBoss()
+
+def main():
+    main.boss = IframeBoss()
diff --git a/src/pyj/read_book/view.pyj b/src/pyj/read_book/view.pyj
index e4eeb350fb..b1c844b5a3 100644
--- a/src/pyj/read_book/view.pyj
+++ b/src/pyj/read_book/view.pyj
@@ -5,14 +5,15 @@ from __python__ import bound_methods, hash_literals
 from elementmaker import E
 from gettext import gettext as _
 
+import read_book.iframe  # noqa
 from ajax import ajax_send
 from book_list.book_details import CLASS_NAME as BD_CLASS_NAME, render_metadata
 from book_list.globals import get_session_data
 from book_list.router import push_state, read_book_mode
 from book_list.theme import get_color
 from dom import add_extra_css, build_rule, clear, set_css, svgicon, unique_id
+from iframe_comm import IframeWrapper
 from modals import error_dialog, warning_dialog
-from read_book.comm import IframeWrapper
 from read_book.content_popup import ContentPopupOverlay
 from read_book.globals import current_book, set_current_spine_item
 from read_book.goto import get_next_section
@@ -22,7 +23,7 @@ from read_book.prefs.font_size import change_font_size_by
 from read_book.prefs.head_foot import render_head_foot
 from read_book.resources import load_resources
 from read_book.search import SearchOverlay, find_in_spine
-from read_book.toc import update_visible_toc_nodes, get_current_toc_nodes
+from read_book.toc import get_current_toc_nodes, update_visible_toc_nodes
 from read_book.touch import set_left_margin_handler, set_right_margin_handler
 from session import get_device_uuid, get_interface_data
 from utils import html_escape, is_ios, parse_url_params, username_key
@@ -163,7 +164,7 @@ class View:
             'show_footnote': self.on_show_footnote,
             'print': self.on_print,
         }
-        self.iframe_wrapper = IframeWrapper(handlers, document.getElementById(iframe_id), 'main', _('Bootstrapping book reader...'))
+        self.iframe_wrapper = IframeWrapper(handlers, document.getElementById(iframe_id), 'read_book.iframe', _('Bootstrapping book reader...'))
         self.search_overlay = SearchOverlay(self)
         self.content_popup_overlay = ContentPopupOverlay(self)
         self.overlay = Overlay(self)
diff --git a/src/pyj/srv.pyj b/src/pyj/srv.pyj
index 86f3ed699d..7d1954e445 100644
--- a/src/pyj/srv.pyj
+++ b/src/pyj/srv.pyj
@@ -1,5 +1,6 @@
 # vim:fileencoding=utf-8
 # License: GPL v3 Copyright: 2015, Kovid Goyal <kovid at kovidgoyal.net>
+# globals: ρσ_get_module
 from __python__ import hash_literals
 
 from gettext import gettext as _
@@ -9,7 +10,6 @@ from ajax import ajax, console_print, set_default_timeout
 from autoreload import create_auto_reload_watcher
 from book_list.globals import main_js
 from book_list.main import main
-from read_book.iframe import init
 
 is_running_in_iframe = False  # Changed before script is loaded in the iframe
 autoreload_enabled = False
@@ -17,7 +17,15 @@ asked_appcache_update = False
 AUTO_UPDATE_THRESHOLD = 1000  # millisecs
 
 if is_running_in_iframe:
-    init()
+    script = document.getElementById('bootstrap')
+    if script:
+        script.parentNode.removeChild(script)  # free up some memory
+    m = ρσ_get_module(window.iframe_entry_point)
+    main = m?.main
+    if main:
+        main()
+    else:
+        console.log('iframe entry_point ' + window.iframe_entry_point + ' not found')
 else:
     start_time = window.performance.now()