diff --git a/examples/certgen.py b/examples/certgen.py
index f157235..d14823e 100644
--- a/examples/certgen.py
+++ b/examples/certgen.py
@@ -45,14 +45,14 @@
     req = crypto.X509Req()
     subj = req.get_subject()
 
-    for (key,value) in name.items():
+    for (key,value) in list(name.items()):
         setattr(subj, key, value)
 
     req.set_pubkey(pkey)
     req.sign(pkey, digest)
     return req
 
-def createCertificate(req, (issuerCert, issuerKey), serial, (notBefore, notAfter), digest="md5"):
+def createCertificate(req, issuerCertKey, serial, validityPeriod, digest="md5"):
     """
     Generate a certificate given a certificate request.
 
@@ -67,6 +67,8 @@
                digest     - Digest method to use for signing, default is md5
     Returns:   The signed certificate in an X509 object
     """
+    (issuerCert, issuerKey) = issuerCertKey
+    (notBefore, notAfter) = validityPeriod
     cert = crypto.X509()
     cert.set_serial_number(serial)
     cert.gmtime_adj_notBefore(notBefore)
diff --git a/examples/mk_simple_certs.py b/examples/mk_simple_certs.py
index 9dfdd2e..a451f95 100644
--- a/examples/mk_simple_certs.py
+++ b/examples/mk_simple_certs.py
@@ -7,11 +7,15 @@
 cakey = createKeyPair(TYPE_RSA, 1024)
 careq = createCertRequest(cakey, CN='Certificate Authority')
 cacert = createCertificate(careq, (careq, cakey), 0, (0, 60*60*24*365*5)) # five years
-open('simple/CA.pkey', 'w').write(crypto.dump_privatekey(crypto.FILETYPE_PEM, cakey))
-open('simple/CA.cert', 'w').write(crypto.dump_certificate(crypto.FILETYPE_PEM, cacert))
+open('simple/CA.pkey', 'w').write(crypto.dump_privatekey(crypto.FILETYPE_PEM, cakey).decode('utf-8')
+)
+open('simple/CA.cert', 'w').write(crypto.dump_certificate(crypto.FILETYPE_PEM, cacert).decode('utf-8')
+)
 for (fname, cname) in [('client', 'Simple Client'), ('server', 'Simple Server')]:
     pkey = createKeyPair(TYPE_RSA, 1024)
     req = createCertRequest(pkey, CN=cname)
     cert = createCertificate(req, (cacert, cakey), 1, (0, 60*60*24*365*5)) # five years
-    open('simple/%s.pkey' % (fname,), 'w').write(crypto.dump_privatekey(crypto.FILETYPE_PEM, pkey))
-    open('simple/%s.cert' % (fname,), 'w').write(crypto.dump_certificate(crypto.FILETYPE_PEM, cert))
+    open('simple/%s.pkey' % (fname,), 'w').write(crypto.dump_privatekey(crypto.FILETYPE_PEM, pkey).decode('utf-8')
+)
+    open('simple/%s.cert' % (fname,), 'w').write(crypto.dump_certificate(crypto.FILETYPE_PEM, cert).decode('utf-8')
+)