diff --git a/Lib/mailcap.py b/Lib/mailcap.py
index 97e3035..7c744bc 100644
--- a/Lib/mailcap.py
+++ b/Lib/mailcap.py
@@ -4,6 +4,22 @@ import os
 
 __all__ = ["getcaps","findmatch"]
 
+
+def lineno_gen():
+    lineno = 0
+    while True:
+        yield lineno
+        lineno += 1
+
+
+def lineno_sort_key(entry):
+    # Sort in ascending order, with unspecified entries at the end
+    if 'lineno' in entry:
+        return 0, entry['lineno']
+    else:
+        return 1, 0
+
+
 # Part 1: top-level interface.
 
 def getcaps():
@@ -17,13 +33,15 @@ def getcaps():
 
     """
     caps = {}
+
+    lineno = lineno_gen()
     for mailcap in listmailcapfiles():
         try:
             fp = open(mailcap, 'r')
         except OSError:
             continue
         with fp:
-            morecaps = readmailcapfile(fp)
+            morecaps, lineno = readmailcapfile(fp, lineno)
         for key, value in morecaps.items():
             if not key in caps:
                 caps[key] = value
@@ -50,7 +68,7 @@ def listmailcapfiles():
 
 # Part 2: the parser.
 
-def readmailcapfile(fp):
+def readmailcapfile(fp, lineno):
     """Read a mailcap file and return a dictionary keyed by MIME type.
 
     Each MIME type is mapped to an entry consisting of a list of
@@ -76,6 +94,7 @@ def readmailcapfile(fp):
         key, fields = parseline(line)
         if not (key and fields):
             continue
+        fields['lineno'] = next(lineno)
         # Normalize the key
         types = key.split('/')
         for j in range(len(types)):
@@ -86,7 +105,7 @@ def readmailcapfile(fp):
             caps[key].append(fields)
         else:
             caps[key] = [fields]
-    return caps
+    return caps, lineno
 
 def parseline(line):
     """Parse one entry in a mailcap file and return a dictionary.
@@ -165,6 +184,7 @@ def lookup(caps, MIMEtype, key=None):
         entries = entries + caps[MIMEtype]
     if key is not None:
         entries = [e for e in entries if key in e]
+    entries = sorted(entries, key=lineno_sort_key)
     return entries
 
 def subst(field, MIMEtype, filename, plist=[]):