diff --git a/bin/python/isc/checkds.py.in b/bin/python/isc/checkds.py.in
index cac226ee4d..b5cbe3fd05 100644
--- a/bin/python/isc/checkds.py.in
+++ b/bin/python/isc/checkds.py.in
@@ -107,6 +107,8 @@ def check(zone, args):
         fp, _ = Popen(cmd, stdout=PIPE).communicate()
 
     for line in fp.splitlines():
+        if type(line) is not str:
+            line = line.decode('ascii')
         rrlist.append(SECRR(line, args.lookaside))
     rrlist = sorted(rrlist, key=lambda rr: (rr.keyid, rr.keyalg, rr.hashalg))
 
@@ -128,6 +130,8 @@ def check(zone, args):
         fp, _ = Popen(cmd, stdin=PIPE, stdout=PIPE).communicate(intods)
 
     for line in fp.splitlines():
+        if type(line) is not str:
+            line = line.decode('ascii')
         klist.append(SECRR(line, args.lookaside))
 
     if len(klist) < 1:
diff --git a/bin/python/isc/keyzone.py.in b/bin/python/isc/keyzone.py.in
index 2451d439e4..bc8c51d72f 100644
--- a/bin/python/isc/keyzone.py.in
+++ b/bin/python/isc/keyzone.py.in
@@ -43,6 +43,8 @@ class keyzone:
         fp, _ = Popen([czpath, "-o", "-", name, filename],
                       stdout=PIPE, stderr=PIPE).communicate()
         for line in fp.splitlines():
+            if type(line) is not str:
+                line = line.decode('ascii')
             if re.search('^[:space:]*;', line):
                 continue
             fields = line.split()