diff --git a/qutebrowser/config/configfiles.py b/qutebrowser/config/configfiles.py
index c2f839c22..5d00d2987 100644
--- a/qutebrowser/config/configfiles.py
+++ b/qutebrowser/config/configfiles.py
@@ -54,7 +54,13 @@ class StateConfig(configparser.ConfigParser):
 
 class YamlConfig:
 
-    """A config stored on disk as YAML file."""
+    """A config stored on disk as YAML file.
+
+    Class attributes:
+        VERSION: The current version number of the config file.
+    """
+
+    VERSION = 1
 
     def __init__(self):
         save_manager = objreg.get('save-manager')
@@ -64,7 +70,7 @@ class YamlConfig:
 
     def _save(self):
         """Save the changed settings to the YAML file."""
-        data = {'global': self.values}
+        data = {'config_version': self.VERSION, 'global': self.values}
         with qtutils.savefile_open(self._filename) as f:
             f.write(textwrap.dedent("""
                 # DO NOT edit this file by hand, qutebrowser will overwrite it.
diff --git a/tests/unit/config/test_configfiles.py b/tests/unit/config/test_configfiles.py
index cb430580c..07b623fa3 100644
--- a/tests/unit/config/test_configfiles.py
+++ b/tests/unit/config/test_configfiles.py
@@ -77,11 +77,12 @@ def test_yaml_config(fake_save_manager, config_tmpdir, old_config, insert):
     print(lines)
 
     assert lines[0].startswith('# DO NOT edit this file by hand,')
+    assert 'config_version: {}'.format(yaml.VERSION) in lines
 
     if old_config is None and not insert:
-        assert lines[3] == 'global: {}'
+        assert 'global: {}' in lines
     else:
-        assert lines[3] == 'global:'
+        assert 'global:' in lines
 
     # WORKAROUND for https://github.com/PyCQA/pylint/issues/574
     if 'magenta' in (old_config or ''):  # pylint: disable=superfluous-parens