diff --git a/tools/cfgupgrade b/tools/cfgupgrade
index 2143ba03b87ce0e9a332e60e5bc360d21f1c9139..5c95ede93fad3778079b2796cdb68b4ed9162303 100755
--- a/tools/cfgupgrade
+++ b/tools/cfgupgrade
@@ -117,6 +117,7 @@ def main():
 
   # We need to keep filenames locally because they might be renamed between
   # versions.
+  options.data_dir = os.path.abspath(options.data_dir)
   options.CONFIG_DATA_PATH = options.data_dir + "/config.data"
   options.SERVER_PEM_PATH = options.data_dir + "/server.pem"
   options.KNOWN_HOSTS_PATH = options.data_dir + "/known_hosts"
diff --git a/tools/cfgupgrade12 b/tools/cfgupgrade12
index 2ebccce3e24ed04b08b2d02f1ce941c0bd7898fc..7f649a79ae3527b691f8bbf2bd0edad7c19d6cf6 100755
--- a/tools/cfgupgrade12
+++ b/tools/cfgupgrade12
@@ -303,6 +303,7 @@ def main():
 
   # We need to keep filenames locally because they might be renamed between
   # versions.
+  options.data_dir = os.path.abspath(options.data_dir)
   options.CONFIG_DATA_PATH = options.data_dir + "/config.data"
   options.SERVER_PEM_PATH = options.data_dir + "/server.pem"
   options.KNOWN_HOSTS_PATH = options.data_dir + "/known_hosts"