diff --git a/src/cmfd_input.F90 b/src/cmfd_input.F90
index 17e7d9ad36..94a6b21e55 100644
--- a/src/cmfd_input.F90
+++ b/src/cmfd_input.F90
@@ -11,7 +11,8 @@ contains
 !===============================================================================
 
   subroutine read_cmfd_xml()
-
+    
+    use error
     use global
     use output
     use string
@@ -28,13 +29,14 @@ contains
     filename = trim(path_input) // "cmfd.xml"
     inquire(FILE=filename, EXIST=file_exists)
     if (.not. file_exists) then
-      ! Since a tallies.xml file is optional, no error is issued here
+      ! CMFD is optional unless it is in on from settings
+      if (cmfd_on) then
+        message = "No CMFD XML file, '" // trim(filename) // "' does not exist!"
+        call fatal_error()
+      end if
       return
     else
 
-      ! turn cmfd flag on  
-!     cmfd_on = .TRUE.
-
       ! tell user
       message = "Reading CMFD XML file..."
       call write_message(5)
diff --git a/src/input_xml.F90 b/src/input_xml.F90
index cebc58e910..3b8e6bda3f 100644
--- a/src/input_xml.F90
+++ b/src/input_xml.F90
@@ -815,7 +815,11 @@ contains
        n_meshes = 0
     else
        n_user_meshes = size(mesh_)
-       n_meshes = n_user_meshes + n_cmfd_meshes
+       if (cmfd_on) then
+         n_meshes = n_user_meshes + n_cmfd_meshes
+       else
+         n_meshes = n_user_meshes
+       end if
        allocate(meshes(n_meshes))
     end if
 
@@ -826,7 +830,11 @@ contains
        call warning()
     else
        n_user_tallies = size(tally_)
-       if (cmfd_on) n_tallies = n_user_tallies + n_cmfd_tallies
+       if (cmfd_on) then
+         n_tallies = n_user_tallies + n_cmfd_tallies
+       else
+         n_tallies = n_user_tallies
+       end if
        allocate(tallies(n_tallies))
     end if
 
@@ -1198,9 +1206,15 @@ contains
     end do
 
     ! Determine number of types of tallies
-    n_analog_tallies = n_user_analog_tallies + n_cmfd_analog_tallies
-    n_tracklength_tallies = n_user_tracklength_tallies + n_cmfd_tracklength_tallies
-    n_current_tallies = n_user_current_tallies + n_cmfd_current_tallies
+    if (cmfd_on) then
+      n_analog_tallies = n_user_analog_tallies + n_cmfd_analog_tallies
+      n_tracklength_tallies = n_user_tracklength_tallies + n_cmfd_tracklength_tallies
+      n_current_tallies = n_user_current_tallies + n_cmfd_current_tallies
+    else
+      n_analog_tallies = n_user_analog_tallies
+      n_tracklength_tallies = n_user_tracklength_tallies
+      n_current_tallies = n_user_current_tallies
+    end if
 
     ! Allocate list of pointers for tallies by type
     allocate(analog_tallies(n_analog_tallies))