diff --git a/tests/grib_proj_string.sh b/tests/grib_proj_string.sh
index e1a60ca56..cc2538dc9 100755
--- a/tests/grib_proj_string.sh
+++ b/tests/grib_proj_string.sh
@@ -97,6 +97,17 @@ set -e
 grep -q "ERROR.*Cannot unpack.*projTargetString.* as double" $tempText
 grep -q "Hint: Try unpacking as string" $tempText
 
+# Unsupported grids
+unsupported_grids="albers space_view equatorial_azimuthal_equidistant transverse_mercator"
+for ug in $unsupported_grids; do
+  ${tools_dir}/grib_set -s gridType=$ug $grib2_sample $tempGrib
+  set +e
+  ${tools_dir}/grib_get -p projString $tempGrib > $tempText 2>&1
+  status=$?
+  set -e
+  [ $status -ne 0 ]
+  grep -q "Not yet implemented" $tempText
+done
 
 # Clean up
 rm -f $tempGrib $tempText