diff --git a/definitions/boot.def b/definitions/boot.def
index bb8991382..25b3f895d 100644
--- a/definitions/boot.def
+++ b/definitions/boot.def
@@ -12,7 +12,8 @@ constant internalVersion=30 : hidden;
 meta checkInternalVersion check_internal_version(internalVersion) : hidden;
 
 # ECC-806: Local concepts precedence order
-transient preferLocalConcepts = 0 : hidden;
+preferLocalConceptsEnvVar = getenv("ECCODES_GRIB_PREFER_LOCAL_CONCEPTS","0") : hidden;
+transient preferLocalConcepts = preferLocalConceptsEnvVar : hidden;
 
 constant defaultTypeOfLevel="unknown" : hidden;
 
diff --git a/tests/grib_ecc-806.sh b/tests/grib_ecc-806.sh
index 95707b812..11c375c56 100755
--- a/tests/grib_ecc-806.sh
+++ b/tests/grib_ecc-806.sh
@@ -17,7 +17,6 @@
 label="grib_ecc-806_test"
 tempGrb=temp.${label}.grb
 tempOut=temp.${label}.txt
-tempErr=temp.${label}.err
 
 # This NCEP grib2 file has the keys
 #   discipline = 0
@@ -36,5 +35,17 @@ res=`${tools_dir}/grib_get -p paramId,shortName,units,name $input`
 res=`${tools_dir}/grib_get -s preferLocalConcepts=1 -p paramId,shortName,units,name $input`
 [ "$res" = "260056 sdwe kg m**-2 Water equivalent of accumulated snow depth (deprecated)" ]
 
+# Test the environment variable too
+export ECCODES_GRIB_PREFER_LOCAL_CONCEPTS=1
+grib_check_key_equals $input preferLocalConceptsEnvVar,preferLocalConcepts '1 1'
+res=`${tools_dir}/grib_get -p paramId,shortName,units,name $input`
+[ "$res" = "260056 sdwe kg m**-2 Water equivalent of accumulated snow depth (deprecated)" ]
+
+export ECCODES_GRIB_PREFER_LOCAL_CONCEPTS=0
+grib_check_key_equals $input preferLocalConceptsEnvVar,preferLocalConcepts '0 0'
+unset ECCODES_GRIB_PREFER_LOCAL_CONCEPTS
+grib_check_key_equals $input preferLocalConceptsEnvVar,preferLocalConcepts '0 0'
+
+
 # Clean up
-rm -f $tempGrb $tempOut $tempErr
+rm -f $tempGrb $tempOut