diff --git a/src/coordinates.F90 b/src/coordinates.F90
index 1218a8b..4747dc1 100644
--- a/src/coordinates.F90
+++ b/src/coordinates.F90
@@ -59,7 +59,7 @@ module coordinates
 
 ! the limits of refinement level
 !
-  integer     , save :: minlev = 1, maxlev = 1, toplev = 1
+  integer     , save :: minlev = 1, maxlev = 1, toplev = -1
 
 ! block indices
 !
@@ -255,7 +255,7 @@ module coordinates
 
 ! set the top level
 !
-    toplev = maxlev
+    if (toplev == -1) toplev = maxlev
 
 ! obtain the domain base division
 !