diff --git a/tests/test_model.py b/tests/test_model.py
index a97f0a0..2711618 100644
--- a/tests/test_model.py
+++ b/tests/test_model.py
@@ -43,3 +43,22 @@
         job = model.Job('job')
         job.copy(self.job)
         self.assertTrue(job.skip_if_matcher)
+
+    def _assert_job_booleans_are_not_none(self, job):
+        self.assertIsNotNone(job.voting)
+        self.assertIsNotNone(job.hold_following_changes)
+
+    def test_job_sets_defaults_for_boolean_attributes(self):
+        job = model.Job('job')
+        self._assert_job_booleans_are_not_none(job)
+
+    def test_metajob_does_not_set_defaults_for_boolean_attributes(self):
+        job = model.Job('^job')
+        self.assertIsNone(job.voting)
+        self.assertIsNone(job.hold_following_changes)
+
+    def test_metajob_copy_does_not_set_undefined_boolean_attributes(self):
+        job = model.Job('job')
+        metajob = model.Job('^job')
+        job.copy(metajob)
+        self._assert_job_booleans_are_not_none(job)
diff --git a/zuul/model.py b/zuul/model.py
index 1786fd9..616ffba 100644
--- a/zuul/model.py
+++ b/zuul/model.py
@@ -452,8 +452,14 @@
         self.failure_pattern = None
         self.success_pattern = None
         self.parameter_function = None
-        self.hold_following_changes = False
-        self.voting = True
+        # A metajob should only supply values for attributes that have
+        # been explicitly provided, so avoid setting boolean defaults.
+        if self.is_metajob:
+            self.hold_following_changes = None
+            self.voting = None
+        else:
+            self.hold_following_changes = False
+            self.voting = True
         self.branches = []
         self._branches = []
         self.files = []
@@ -467,6 +473,10 @@
     def __repr__(self):
         return '<Job %s>' % (self.name)
 
+    @property
+    def is_metajob(self):
+        return self.name.startswith('^')
+
     def copy(self, other):
         if other.failure_message:
             self.failure_message = other.failure_message
@@ -488,8 +498,11 @@
             self.skip_if_matcher = other.skip_if_matcher.copy()
         if other.swift:
             self.swift.update(other.swift)
-        self.hold_following_changes = other.hold_following_changes
-        self.voting = other.voting
+        # Only non-None values should be copied for boolean attributes.
+        if other.hold_following_changes is not None:
+            self.hold_following_changes = other.hold_following_changes
+        if other.voting is not None:
+            self.voting = other.voting
 
     def changeMatches(self, change):
         matches_branch = False
@@ -1269,8 +1282,7 @@
         if name in self.jobs:
             return self.jobs[name]
         job = Job(name)
-        if name.startswith('^'):
-            # This is a meta-job
+        if job.is_metajob:
             regex = re.compile(name)
             self.metajobs.append((regex, job))
         else: