diff --git a/patroni/postgresql.py b/patroni/postgresql.py
index <HASH>..<HASH> 100644
--- a/patroni/postgresql.py
+++ b/patroni/postgresql.py
@@ -1216,7 +1216,8 @@ class Postgresql(object):
                 if data:
                     data = data.decode('utf-8').splitlines()
                     # pg_controldata output depends on major verion. Some of parameters are prefixed by 'Current '
-                    result = {l.split(':')[0].replace('Current ', '', 1): l.split(':', 1)[1].strip() for l in data if l}
+                    result = {l.split(':')[0].replace('Current ', '', 1): l.split(':', 1)[1].strip() for l in data
+                              if l and ':' in l}
             except subprocess.CalledProcessError:
                 logger.exception("Error when calling pg_controldata")
         return result
check if output lines of controldata are possible to split (#<I>)

Otherwise it fails with scary stacktrace