diff --git a/src/eigenvalue.F90 b/src/eigenvalue.F90
index 37edb922c4..cd95568849 100644
--- a/src/eigenvalue.F90
+++ b/src/eigenvalue.F90
@@ -536,12 +536,12 @@ contains
         m % n_dimension = 3
         allocate(m % dimension(3))
         m % dimension = n
+        
+        ! determine width
+        m % width = (m % upper_right - m % lower_left) / m % dimension
+        
       end if
 
-      ! allocate and determine width
-      allocate(m % width(3))
-      m % width = (m % upper_right - m % lower_left) / m % dimension
-
       ! allocate p
       allocate(entropy_p(1, m % dimension(1), m % dimension(2), &
            m % dimension(3)))
diff --git a/src/input_xml.F90 b/src/input_xml.F90
index a55fc363f4..522427807d 100644
--- a/src/input_xml.F90
+++ b/src/input_xml.F90
@@ -3135,6 +3135,12 @@ contains
                 call fatal_error()
               end if
               
+              if (.not. allocated(entropy_mesh % dimension)) then
+                message = "No dimension specified on entropy mesh for " //
+                          "meshlines on plot " // trim(to_str(pl % id))
+                call fatal_error()
+              end if
+              
               pl % meshlines_mesh => entropy_mesh
 
             case ('tally')