diff --git a/jenkins_jobs/formatter.py b/jenkins_jobs/formatter.py
index 66724d274..224ad643f 100644
--- a/jenkins_jobs/formatter.py
+++ b/jenkins_jobs/formatter.py
@@ -40,7 +40,7 @@ def deep_format(obj, paramdict, allow_empty=False):
             else:
                 ret = CustomFormatter(allow_empty).format(obj, **paramdict)
         except KeyError as exc:
-            missing_key = exc.message
+            missing_key = exc.args[0]
             desc = "%s parameter missing to format %s\nGiven:\n%s" % (
                 missing_key, obj, pformat(paramdict))
             raise JenkinsJobsException(desc)
@@ -55,7 +55,7 @@ def deep_format(obj, paramdict, allow_empty=False):
                 ret[CustomFormatter(allow_empty).format(item, **paramdict)] = \
                     deep_format(obj[item], paramdict, allow_empty)
             except KeyError as exc:
-                missing_key = exc.message
+                missing_key = exc.args[0]
                 desc = "%s parameter missing to format %s\nGiven:\n%s" % (
                     missing_key, obj, pformat(paramdict))
                 raise JenkinsJobsException(desc)