diff --git a/data/processing/subdomain.py b/data/processing/subdomain.py
index 8ccc6a4..6ddcf40 100644
--- a/data/processing/subdomain.py
+++ b/data/processing/subdomain.py
@@ -26,7 +26,7 @@ domain = np.stack((artha, buoy))
 domain.sort(axis=0)
 log.debug(f"domain: {domain}")
 
-margin = config.getfloat("out", "margin", default=0.002)
+margin = config.getfloat("out", "margin", fallback=0.002)
 domain[0] -= margin
 domain[1] += margin
 log.debug(f"domain: {domain}")