diff --git a/resources/viewer/hyphenate/Hyphenator.js b/resources/viewer/hyphenate/Hyphenator.js
index 0296bb5053..657246d9c3 100644
--- a/resources/viewer/hyphenate/Hyphenator.js
+++ b/resources/viewer/hyphenate/Hyphenator.js
@@ -2022,7 +2022,8 @@ var Hyphenator = (function (window) {
 						if (n.nodeType === 3 && n.data.length >= min) { //type 3 = #text -> hyphenate!
 							n.data = n.data.replace(Hyphenator.languages[lang].genRegExp, hyphenate);
 						} else if (n.nodeType === 1) {
-							if (n.lang !== '') {
+                            // Modified by Kovid to use element lang only if it has been loaded
+							if (n.lang !== '' && Hyphenator.languages.hasOwnProperty(n.lang)) {
 								Hyphenator.hyphenate(n, n.lang);
 							} else {
 								Hyphenator.hyphenate(n, lang);
@@ -2139,4 +2140,4 @@ if (Hyphenator.isBookmarklet()) {
 	Hyphenator.config({displaytogglebox: true, intermediatestate: 'visible', doframes: true});
 	Hyphenator.config(Hyphenator.getConfigFromURI());
 	Hyphenator.run();
-}
\ No newline at end of file
+}
diff --git a/src/calibre/gui2/viewer/documentview.py b/src/calibre/gui2/viewer/documentview.py
index 74224ccb44..92c06a47f0 100644
--- a/src/calibre/gui2/viewer/documentview.py
+++ b/src/calibre/gui2/viewer/documentview.py
@@ -23,7 +23,8 @@ from calibre.constants import iswindows
 from calibre import prints, guess_type
 from calibre.gui2.viewer.keys import SHORTCUTS
 
-bookmarks = referencing = hyphenation = jquery = jquery_scrollTo = hyphenator = images =None
+bookmarks = referencing = hyphenation = jquery = jquery_scrollTo = \
+        hyphenator = images = hyphen_pats = None
 
 def load_builtin_fonts():
     base = P('fonts/liberation/*.ttf')
@@ -202,7 +203,8 @@ class Document(QWebPage):
         self.loaded_javascript = False
 
     def load_javascript_libraries(self):
-        global bookmarks, referencing, hyphenation, jquery, jquery_scrollTo, hyphenator, images
+        global bookmarks, referencing, hyphenation, jquery, jquery_scrollTo, \
+                hyphenator, images, hyphen_pats
         if self.loaded_javascript:
             return
         self.loaded_javascript = True
@@ -234,12 +236,19 @@ class Document(QWebPage):
             return l.lower().replace('_', '-')
         if hyphenator is None:
             hyphenator = P('viewer/hyphenate/Hyphenator.js', data=True).decode('utf-8')
-        self.javascript(hyphenator)
+        if hyphen_pats is None:
+            hyphen_pats = []
+            for x in glob.glob(P('viewer/hyphenate/patterns/*.js',
+                allow_user_override=False)):
+                with open(x, 'rb') as f:
+                    hyphen_pats.append(f.read().decode('utf-8'))
+            hyphen_pats = u'\n'.join(hyphen_pats)
+
+        self.javascript(hyphenator+hyphen_pats)
         p = P('viewer/hyphenate/patterns/%s.js'%lang_name(lang))
         if not os.path.exists(p):
             lang = default_lang
             p = P('viewer/hyphenate/patterns/%s.js'%lang_name(lang))
-        self.javascript(open(p, 'rb').read().decode('utf-8'))
         self.loaded_lang = lang_name(lang)
 
     @pyqtSignature("")