2 files changed, 9 insertions, 3 deletions

diff --git a/src/mailman/commands/cli_control.py b/src/mailman/commands/cli_control.py
index 8349feb60..b5a79b820 100644
--- a/src/mailman/commands/cli_control.py
+++ b/src/mailman/commands/cli_control.py
@@ -121,7 +121,11 @@ class Start:
         os.setsid()
         # Instead of cd'ing to root, cd to the Mailman runtime directory.
         # However, before we do that, set an environment variable used by the
-        # subprocesses to calculate their path to the $VAR_DIR.
+        # subprocesses to calculate their path to the $VAR_DIR.  Before we
+        # chdir() though, calculate the absolute path to the configuration
+        # file.
+        config_path = (os.path.abspath(args.config)
+                       if args.config else None)
         os.environ['MAILMAN_VAR_DIR'] = config.VAR_DIR
         os.chdir(config.VAR_DIR)
         # Exec the master watcher.
@@ -131,8 +135,8 @@ class Start:
             ]
         if args.force:
             execl_args.append('--force')
-        if args.config:
-            execl_args.extend(['-C', args.config])
+        if config_path:
+            execl_args.extend(['-C', config_path])
         qlog.debug('starting: %s', execl_args)
         os.execl(*execl_args)
         # We should never get here.
diff --git a/src/mailman/docs/NEWS.rst b/src/mailman/docs/NEWS.rst
index 892cc52c4..392eccea6 100644
--- a/src/mailman/docs/NEWS.rst
+++ b/src/mailman/docs/NEWS.rst
@@ -55,6 +55,8 @@ Commands
  * `bin/mailman aliases` loses the `--output`, `--format`, and `--simple`
    arguments, and adds a `--directory` argument.  This is necessary to support
    the Postfix `relay_domains` support.
+ * `bin/mailman start` was passing the wrong relative path to its runner
+   subprocesses when -C was given.  LP: #982551
 
 
 3.0 beta 2 -- "Freeze"