diff --git a/libmproxy/certutils.py b/libmproxy/certutils.py
index f393648d4..95dcc0fef 100644
--- a/libmproxy/certutils.py
+++ b/libmproxy/certutils.py
@@ -1,4 +1,4 @@
-import os, ssl, hashlib, socket, time
+import os, ssl, hashlib, socket, time, datetime
 from pyasn1.type import univ, constraint, char, namedtype, tag
 from pyasn1.codec.der.decoder import decode
 import OpenSSL
@@ -157,11 +157,13 @@ class SSLCert:
 
     @property
     def notbefore(self):
-        return self.cert.get_notBefore()
+        t = self.cert.get_notBefore()
+        return datetime.datetime.strptime(t, "%Y%m%d%H%M%SZ")
 
     @property
     def notafter(self):
-        return self.cert.get_notAfter()
+        t = self.cert.get_notAfter()
+        return datetime.datetime.strptime(t, "%Y%m%d%H%M%SZ")
 
     @property
     def has_expired(self):
diff --git a/libmproxy/console/flowdetailview.py b/libmproxy/console/flowdetailview.py
index 6c5e7fe20..e589d01df 100644
--- a/libmproxy/console/flowdetailview.py
+++ b/libmproxy/console/flowdetailview.py
@@ -55,8 +55,8 @@ class FlowDetailsView(urwid.ListBox):
                 text.append(urwid.Text([("head", "Server Certificate:")]))
                 parts = [
                     ["Type", "%s, %s bits"%c.keyinfo],
-                    ["Valid to", c.notafter],
-                    ["Valid from", c.notbefore],
+                    ["Valid to", str(c.notafter)],
+                    ["Valid from", str(c.notbefore)],
                     ["Serial", str(c.serial)],
                 ]