diff --git a/tardis/io/schemas/montecarlo.yml b/tardis/io/schemas/montecarlo.yml
index 0e6df3c7988..e8a77ad963e 100644
--- a/tardis/io/schemas/montecarlo.yml
+++ b/tardis/io/schemas/montecarlo.yml
@@ -39,7 +39,7 @@ properties:
     properties:
       start:
         type: quantity
-        default: 0 angstrom
+        default: 1 angstrom
       end:
         type: quantity
         default: inf angstrom