diff --git a/tests/grib_copy.sh b/tests/grib_copy.sh
index cc93fc088..4b7f21f23 100755
--- a/tests/grib_copy.sh
+++ b/tests/grib_copy.sh
@@ -44,7 +44,7 @@ r2=`${tools_dir}/grib_get -n ls $temp`
 [ "$r1" = "$r2" ]
 
 
-echo "Test: ECC-1086..."
+echo "Test: ECC-1086 invalid message ..."
 # -------------------------
 # This file is 179 bytes long. We chop the last byte to create
 # an invalid GRIB message (Final 7777 is 777)
@@ -80,6 +80,16 @@ set -e
 count=`${tools_dir}/grib_count $temp`
 [ $count -eq 43 ]
 
+
+echo "Test: ECC-539 input=output ..."
+# -----------------------
+set +e
+${tools_dir}/grib_copy  $temp $temp
+status=$?
+set -e
+[ $status -ne 0 ]
+
+
 #${tools_dir}/grib_copy -w count=1 -X 57143 $input $temp #Last msg
 #r1=`${tools_dir}/grib_get -w count=37 -n ls $input`
 #r2=`${tools_dir}/grib_get -n ls $temp`
diff --git a/tests/grib_set.sh b/tests/grib_set.sh
index 31e945110..325d4168e 100755
--- a/tests/grib_set.sh
+++ b/tests/grib_set.sh
@@ -72,5 +72,11 @@ done
 ${tools_dir}/grib_set -s centre=289 $ECCODES_SAMPLES_PATH/GRIB2.tmpl $outfile
 ${tools_dir}/grib_dump -O $outfile | grep -q 'centre = 289.*Zambia'
 
+# ECC-539: avoid output being the same as input
+set +e
+${tools_dir}/grib_set -s centre=0 $outfile $outfile
+status=$?
+set -e
+[ $status -ne 0 ]
 
 rm -f $outfile