diff --git a/CondTools/SiStrip/scripts/SiStripDAQPopCon.py b/CondTools/SiStrip/scripts/SiStripDAQPopCon.py
index 342b907369ceb..2e7645d58ca56 100755
--- a/CondTools/SiStrip/scripts/SiStripDAQPopCon.py
+++ b/CondTools/SiStrip/scripts/SiStripDAQPopCon.py
@@ -83,7 +83,7 @@ def runjob(args):
     pipe = subprocess.Popen(command, shell=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
     atexit.register(partial(helper.kill_subproc_noexcept, pipe))
     out = pipe.communicate()[0]
-    if isinstance(out, byte):
+    if isinstance(out, bytes):
         out = out.decode("utf8", "replace")
     logging.info('\n%s\n' % out)
     logging.info('@@@CMSSW job return code = %d@@@' % pipe.returncode)