diff --git a/src/pyj/read_book/iframe.pyj b/src/pyj/read_book/iframe.pyj
index b0c4ef2015..3203e92b86 100644
--- a/src/pyj/read_book/iframe.pyj
+++ b/src/pyj/read_book/iframe.pyj
@@ -4,7 +4,6 @@ from __python__ import bound_methods, hash_literals
 
 import traceback
 from aes import GCM
-from elementmaker import E
 from gettext import install, gettext as _
 from read_book.cfi import at_current, scroll_to as scroll_to_cfi
 from read_book.globals import set_boss, set_current_spine_item, current_layout_mode, current_spine_item, set_layout_mode
@@ -45,6 +44,7 @@ class IframeBoss:
             'display': self.display,
             'scroll_to_anchor': self.on_scroll_to_anchor,
             'next_screen': self.on_next_screen,
+            'change_font_size': self.change_font_size,
         }
         self.last_window_ypos = 0
 
@@ -135,11 +135,26 @@ class IframeBoss:
         else:
             paged_scroll_by_page(backwards, True)
 
+    def apply_font_size(self):
+        document.documentElement.style.fontSize = document.body.style.fontSize = '{}px'.format(opts.base_font_size)
+
+    def apply_colors(self):
+        for elem in (document.documentElement, document.body):
+            elem.style.color = opts.color_scheme.foreground
+            elem.style.backgroundColor = opts.color_scheme.background
+
+    def change_font_size(self, data):
+        if data.base_font_size? and data.base_font_size != opts.base_font_size:
+            opts.base_font_size = data.base_font_size
+            self.apply_font_size()
+
     def content_loaded(self):
         document.documentElement.style.overflow = 'hidden'
-        document.body.appendChild(
-            E.style(str.format('html, body {{ color: {} !important; background-color: {} !important }}', opts.color_scheme.foreground, opts.color_scheme.background))
-        )
+        # document.body.appendChild(
+        #     E.style()  # TODO: User style sheet
+        # )
+        self.apply_colors()
+        self.apply_font_size()
         self.do_layout()
         if self.mathjax:
             return apply_mathjax(self.mathjax, self.book.manifest.link_uid, self.content_loaded_stage2)
diff --git a/src/pyj/read_book/settings.pyj b/src/pyj/read_book/settings.pyj
index 18a5723630..2519f2c1d3 100644
--- a/src/pyj/read_book/settings.pyj
+++ b/src/pyj/read_book/settings.pyj
@@ -10,5 +10,6 @@ def apply_settings(settings):
     opts.margin_left = max(0, settings.margin_left or 0)
     opts.margin_right = max(0, settings.margin_right or 0)
     opts.color_scheme = settings.color_scheme
+    opts.base_font_size = max(8, min(settings.base_font_size or 16, 64))
 
 apply_settings()
diff --git a/src/pyj/read_book/view.pyj b/src/pyj/read_book/view.pyj
index 511456c059..22687c36a9 100644
--- a/src/pyj/read_book/view.pyj
+++ b/src/pyj/read_book/view.pyj
@@ -248,6 +248,7 @@ class View:
             'read_mode': sd.get('read_mode'),
             'columns_per_screen': sd.get('columns_per_screen'),
             'color_scheme': self.get_color_scheme(True),
+            'base_font_size': sd.get('base_font_size'),
         }
         initial_position = initial_position or {'replace_history':False}
         self.currently_showing = {'name':name, 'settings':settings, 'initial_position':initial_position, 'loading':True}
@@ -320,3 +321,6 @@ class View:
     def on_content_loaded(self):
         self.hide_loading()
         # self.overlay.show()
+
+    def update_font_size(self):
+        self.send_message('change_font_size', base_font_size=get_session_data().get('base_font_size'))
diff --git a/src/pyj/session.pyj b/src/pyj/session.pyj
index 3211efe586..bd0704ce4a 100644
--- a/src/pyj/session.pyj
+++ b/src/pyj/session.pyj
@@ -28,6 +28,7 @@ defaults = {
     'columns_per_screen': {'portrait':0, 'landscape':0},
     'current_color_scheme': 'white',
     'user_color_schemes': {},
+    'base_font_size': 16,
 }
 
 is_local_setting = {
@@ -40,6 +41,7 @@ is_local_setting = {
     'max_text_width': True,
     'columns_per_screen': True,
     'current_color_scheme': True,
+    'base_font_size': True,
 }
 
 def storage_available(which):