diff --git a/src/calibre/libunzip.py b/src/calibre/libunzip.py
index 86dc2de4a4..172d1ce512 100644
--- a/src/calibre/libunzip.py
+++ b/src/calibre/libunzip.py
@@ -40,15 +40,15 @@ def extract(filename, dir):
     """
     Extract archive C{filename} into directory C{dir}
     """
-    zf = zipfile.ZipFile( filename )
+    zf = zipfile.ZipFile(filename)
     zf.extractall(dir)
 
-def extract_member(filename, match=re.compile(r'\.(jpg|jpeg|gif|png)\s*$',
-    re.I), sort_alphabetically=False):
+def extract_member(filename, match=re.compile(r'\.(jpg|jpeg|gif|png)\s*$', re.I), sort_alphabetically=False):
     zf = zipfile.ZipFile(filename)
     names = list(zf.namelist())
     if sort_alphabetically:
-        names.sort()
+        from calibre.utils.icu import numeric_sort_key
+        names.sort(key=numeric_sort_key)
     for name in names:
         if match.search(name):
             return name, zf.read(name)
diff --git a/src/calibre/utils/unrar.py b/src/calibre/utils/unrar.py
index a7b46b1f5d..96f0d2820b 100644
--- a/src/calibre/utils/unrar.py
+++ b/src/calibre/utils/unrar.py
@@ -185,8 +185,9 @@ def extract_member(stream, match=re.compile(r'\.(jpg|jpeg|gif|png)\s*$', re.I),
             return h['filename'], et.getvalue()
 
 def extract_first_alphabetically(stream):
+    from calibre.utils.icu import numeric_sort_key
     names_ = sorted([x for x in names(stream) if os.path.splitext(x)[1][1:].lower() in
-            {'png', 'jpg', 'jpeg', 'gif'}])
+            {'png', 'jpg', 'jpeg', 'gif'}], key=numeric_sort_key)
     return extract_member(stream, name=names_[0], match=None)
 
 # Test normal RAR file {{{