1 files changed, 16 insertions, 1 deletions

diff --git a/bumper b/bumper
index ef06fef..624c358 100755
--- a/bumper
+++ b/bumper
@@ -30,9 +30,15 @@ class Bumper(cliapp.Application):
     def process_args(self, args):
         project_name = self.get_project_name()
         version = self.get_version(args)
-        version_py = self.find_version_py()
         print 'Releasing {} version {}'.format(project_name, version)
 
+        current_version = self.get_current_version()
+        if not self.version_is_newer(version, current_version):
+            raise cliapp.AppException(
+                'New version {} is older than current version {}'.format(
+                    version, current_version))
+
+        version_py = self.find_version_py()
         print '... {}'.format(version_py)
         self.write_version_py(version_py, version, '')
 
@@ -81,6 +87,15 @@ class Bumper(cliapp.Application):
             raise cliapp.AppException('Too many version.py in project')
         return version_pys[0]
 
+    def get_current_version(self):
+        return cliapp.runcmd(['python', 'setup.py', '--version']).strip()
+
+    def version_is_newer(self, v1, v2):
+        '''Is v1 newer than v2?'''
+        vi1 = self.parse_version_info(v1, None)
+        vi2 = self.parse_version_info(v2, None)
+        return vi1 > vi2
+
     def update_debian_changelog(self, version, msg):
         debian_version = '{}-1'.format(version)
         cliapp.runcmd(['dch', '-v', debian_version, msg])