diff --git a/bld/CLMBuildNamelist.pm b/bld/CLMBuildNamelist.pm
index a8314767346..626a0bc51ca 100755
--- a/bld/CLMBuildNamelist.pm
+++ b/bld/CLMBuildNamelist.pm
@@ -2105,7 +2105,7 @@ sub setup_logic_cnfire {
 sub setup_logic_cnprec {
   my ($opts, $nl_flags, $definition, $defaults, $nl, $physv) = @_;
 
-  if ( $physv->as_long() >= $physv->as_long("clm5_0") && &value_is_true($nl->get_value('use_cn')) ) {
+  if ( $physv->as_long() >= $physv->as_long("clm4_5") && &value_is_true($nl_flags->{'use_cn'}) ) {
      add_default($opts, $nl_flags->{'inputdata_rootdir'}, $definition, $defaults,
                  $nl, 'ncrit', 'use_cn'=>$nl_flags->{'use_cn'});
      add_default($opts, $nl_flags->{'inputdata_rootdir'}, $definition, $defaults,
diff --git a/bld/namelist_files/namelist_defaults_clm4_5.xml b/bld/namelist_files/namelist_defaults_clm4_5.xml
index f78b54ef5c7..325c358bb7d 100644
--- a/bld/namelist_files/namelist_defaults_clm4_5.xml
+++ b/bld/namelist_files/namelist_defaults_clm4_5.xml
@@ -434,6 +434,7 @@ attributes from the config_cache.xml file (with keys converted to upper-case).
 <use_nguardrail phys="clm5_0" use_cn=".true." >.true.</use_nguardrail>
 
 <ncrit    phys="clm5_0" use_cn=".true.">1.d-9</ncrit>
+<ncrit    phys="clm4_5" use_cn=".true.">1.d-8</ncrit>
 <cnegcrit phys="clm5_0" use_cn=".true.">-6.d+1</cnegcrit>
 <nnegcrit phys="clm5_0" use_cn=".true.">-6.d+0</nnegcrit>
 <cnegcrit phys="clm4_5" use_cn=".true.">-6.d+2</cnegcrit>