diff --git a/resources/default_tweaks.py b/resources/default_tweaks.py
index 993c8f74f9..a3008d7a5d 100644
--- a/resources/default_tweaks.py
+++ b/resources/default_tweaks.py
@@ -523,6 +523,14 @@ default_tweak_format = None
 # your library and your personal editing style.
 preselect_first_completion = False
 
+#: Completion mode when editing authors/tags/series/etc.
+# By default, when completing items, calibre will show you all the candidates
+# that start with the text you have already typed. You can instead have it show
+# all candidates that contain the text you have already typed. To do this, set
+# completion_mode to 'contains'. For example, if you type asi it will match both
+# Asimov and Quasimodo, whereas the default behavior would match only Asimov.
+completion_mode = 'prefix'
+
 #: Recognize numbers inside text when sorting
 # This means that when sorting on text fields like title the text "Book 2"
 # will sort before the text "Book 100". If you want this behavior, set
diff --git a/src/calibre/gui2/complete2.py b/src/calibre/gui2/complete2.py
index 3214cb5fff..25c7ff3fc2 100644
--- a/src/calibre/gui2/complete2.py
+++ b/src/calibre/gui2/complete2.py
@@ -14,11 +14,14 @@ from PyQt4.Qt import (QLineEdit, QAbstractListModel, Qt, pyqtSignal, QObject,
         QApplication, QListView, QPoint, QModelIndex, QFont, QFontInfo)
 
 from calibre.constants import isosx, get_osx_version
-from calibre.utils.icu import sort_key, primary_startswith
+from calibre.utils.icu import sort_key, primary_startswith, primary_icu_find
 from calibre.gui2 import NONE
 from calibre.gui2.widgets import EnComboBox, LineEditECM
 from calibre.utils.config import tweaks
 
+def containsq(x, prefix):
+    return primary_icu_find(prefix, x)[0] != -1
+
 class CompleteModel(QAbstractListModel):  # {{{
 
     def __init__(self, parent=None):
@@ -45,8 +48,8 @@ class CompleteModel(QAbstractListModel):  # {{{
             return
         subset = prefix.startswith(old_prefix)
         universe = self.current_items if subset else self.all_items
-        self.current_items = tuple(x for x in universe if primary_startswith(x,
-            prefix))
+        func = primary_startswith if tweaks['completion_mode'] == 'prefix' else containsq
+        self.current_items = tuple(x for x in universe if func(x, prefix))
         self.reset()
 
     def rowCount(self, *args):
diff --git a/src/calibre/utils/icu.py b/src/calibre/utils/icu.py
index 27168bc618..9e0df01b85 100644
--- a/src/calibre/utils/icu.py
+++ b/src/calibre/utils/icu.py
@@ -247,6 +247,9 @@ def primary_find(pat, src):
     if _icu_not_ok:
         from calibre.utils.filenames import ascii_text
         return py_find(ascii_text(pat), ascii_text(src))
+    return primary_icu_find(pat, src)
+
+def primary_icu_find(pat, src):
     try:
         return icu_find(_primary_collator, pat, src)
     except AttributeError: