diff --git a/src/mra.yaml.sample b/src/mra.yaml.sample
index 9c75e73b113d563e3b29f20ebdb0f64d61b33d2b..64525bd225af77c856d2e9042bcddba35c194cfa 100644
--- a/src/mra.yaml.sample
+++ b/src/mra.yaml.sample
@@ -34,7 +34,7 @@ mapfile:
         raster:
             resample: average
             scale: auto
-            nodata: off
+            nodata: "off"
 
 
 debug: