diff --git a/sources/user_problem.F90 b/sources/user_problem.F90
index 2cb2f2c..d1875c2 100644
--- a/sources/user_problem.F90
+++ b/sources/user_problem.F90
@@ -36,7 +36,7 @@ module user_problem
   real(kind=8), save :: dens = 1.00d+00
   real(kind=8), save :: bamp = 1.00d+00
   real(kind=8), save :: bgui = 0.00d+00
-  real(kind=8), save :: dlta = 3.16d-03
+  real(kind=8), save :: dlta = 1.00d-02
   real(kind=8), save :: pres = 5.00d-01
   real(kind=8), save :: pmag = 5.00d-01
   real(kind=8), save :: ptot = 1.00d+00
@@ -118,14 +118,6 @@ module user_problem
       status = 1
       return
     end if
-    call get_parameter("delta", dlta)
-    if (dlta <= 0.0d+00) then
-      if (verbose) &
-        call print_message(loc, &
-                      "The initial thickness must be positive (delta > 0.0)!")
-      status = 1
-      return
-    end if
     call get_parameter("resistivity", eta)
     if (eta < 0.0d+00) then
       if (verbose) &
@@ -134,6 +126,15 @@ module user_problem
       return
     else
       resistive = .true.
+      dlta = sqrt(eta)
+    end if
+    call get_parameter("delta", dlta)
+    if (dlta <= 0.0d+00) then
+      if (verbose) &
+        call print_message(loc, &
+                      "The initial thickness must be positive (delta > 0.0)!")
+      status = 1
+      return
     end if
 
     pmag = 0.5d+00 * (bamp**2 + bgui**2)