diff --git a/bld/CLMBuildNamelist.pm b/bld/CLMBuildNamelist.pm
index a5b19dd62b..86b9943f34 100755
--- a/bld/CLMBuildNamelist.pm
+++ b/bld/CLMBuildNamelist.pm
@@ -2743,6 +2743,13 @@ SIMYR:    foreach my $sim_yr ( @sim_years ) {
         $log->fatal_error("$useinitvar is being set for you but a $var was not found, so $useinitvar, init_interp_attributes, and finidat must not be set correctly for this configuration in the namelist_default file" );
      }
   }
+
+  # this check has to be here and not earlier since use_init_interp is set here and hillslope is already set above in setup_logic_hillslope
+  if ( &value_is_true($nl->get_value($useinitvar)) && value_is_true($nl->get_value("use_hillslope")) ) {
+     $log->warning("WARNING: You have set use_hillslope while $useinitvar is TRUE.\n This means all hillslope columns in a gridcell will read identical values" .
+                   " from initial conditions. If you are sure you want this behaviour:")
+  }
+
 } # end initial conditions
 
 #-------------------------------------------------------------------------------
diff --git a/bld/unit_testers/build-namelist_test.pl b/bld/unit_testers/build-namelist_test.pl
index 8b2827b069..5424c54352 100755
--- a/bld/unit_testers/build-namelist_test.pl
+++ b/bld/unit_testers/build-namelist_test.pl
@@ -1301,6 +1301,10 @@ sub cat_and_create_namelistinfile {
                                      namelst=>"fsurdat='build-namelist_test.pl'",
                                      phys=>"clm6_0",
                                    },
+     "hillslope with init_interp"=>{ options=>"-bgc bgc -envxml_dir .",
+                                     namelst=>"use_init_interp=.true.,use_hillslope=.true.",
+                                     phys=>"clm6_0",
+                                   },
                );
 foreach my $key ( keys(%warntest) ) {
    print( "$key\n" );
diff --git a/cime_config/testdefs/testmods_dirs/clm/Hillslope/shell_commands b/cime_config/testdefs/testmods_dirs/clm/Hillslope/shell_commands
index 6f3602d2e6..a2759b51b4 100644
--- a/cime_config/testdefs/testmods_dirs/clm/Hillslope/shell_commands
+++ b/cime_config/testdefs/testmods_dirs/clm/Hillslope/shell_commands
@@ -2,3 +2,6 @@
 DIN_LOC_ROOT=$(./xmlquery --value DIN_LOC_ROOT)
 meshfile=$DIN_LOC_ROOT/lnd/clm2/testdata/ESMFmesh_10x15_synthetic_cosphill_1.0.nc
 ./xmlchange ATM_DOMAIN_MESH=${meshfile},LND_DOMAIN_MESH=${meshfile}
+
+# -ignore_warnings is needed as long as we don't allow use_hillslope and use_init_interp together
+./xmlchange --append CLM_BLDNML_OPTS=-ignore_warnings