diff --git a/server/src/main/java/au/org/aodn/ogcapi/server/core/util/GeometryUtils.java b/server/src/main/java/au/org/aodn/ogcapi/server/core/util/GeometryUtils.java
index f9748070..1d629f6e 100644
--- a/server/src/main/java/au/org/aodn/ogcapi/server/core/util/GeometryUtils.java
+++ b/server/src/main/java/au/org/aodn/ogcapi/server/core/util/GeometryUtils.java
@@ -33,6 +33,7 @@
 public class GeometryUtils {
 
     protected static final int PRECISION = 15;
+    public static final String NON_SPECIFIED_MULTIPOLYGON = "non-specified";
 
     @Getter
     protected static GeometryFactory factory = new GeometryFactory(new PrecisionModel(), 4326);
@@ -210,15 +211,18 @@ public static String convertToGeoJson(LiteralExpressionImpl literalExpression, C
             return r;
         }
     }
+
     /**
      * Many code require static access to this function, hence we will init it somewhere as bean and then
      * set it to the static instance for sharing
+     *
      * @param input - A geometry text input
      * @return - The converted geometry
      */
     public static Optional<Geometry> readGeometry(Object input) {
         return self.readCachedGeometry(input);
     }
+
     /**
      * Please use this function as it contains the parser with enough decimal to make it work.
      *
@@ -235,8 +239,7 @@ public Optional<Geometry> readCachedGeometry(Object input) {
                 j = (String) input;
             }
             return Optional.of(json.read(j));
-        }
-        catch (IOException e) {
+        } catch (IOException e) {
             // Do nothing
         }
         return Optional.empty();
@@ -295,7 +298,7 @@ public static ReferencedEnvelope toReferencedEnvelope(Coordinate[] coordinates,
      * @throws IllegalArgumentException if the input is not valid GeoJSON
      */
     public static String convertToWkt(Object geoJsonGeometry) {
-        if (geoJsonGeometry == null) {
+        if (geoJsonGeometry == null || geoJsonGeometry.toString().equals(NON_SPECIFIED_MULTIPOLYGON)) {
             return null;
         }
 
diff --git a/server/src/test/java/au/org/aodn/ogcapi/server/core/util/GeometryUtilsTest.java b/server/src/test/java/au/org/aodn/ogcapi/server/core/util/GeometryUtilsTest.java
index 5bc3ac08..022ea40f 100644
--- a/server/src/test/java/au/org/aodn/ogcapi/server/core/util/GeometryUtilsTest.java
+++ b/server/src/test/java/au/org/aodn/ogcapi/server/core/util/GeometryUtilsTest.java
@@ -28,9 +28,9 @@ protected GeometryCollection convertToGeometryCollection(
         List<Geometry> geometries = new ArrayList<>();
 
         // Iterate through the FeatureCollection and extract geometries
-        try(FeatureIterator<SimpleFeature> features = featureCollection.features()) {
-            while(features.hasNext()) {
-                Geometry geometry = (Geometry)(features.next()).getDefaultGeometry();
+        try (FeatureIterator<SimpleFeature> features = featureCollection.features()) {
+            while (features.hasNext()) {
+                Geometry geometry = (Geometry) (features.next()).getDefaultGeometry();
                 geometries.add(geometry);
             }
         }
@@ -41,8 +41,10 @@ protected GeometryCollection convertToGeometryCollection(
         // Create and return a GeometryCollection from the array of geometries
         return geometryFactory.createGeometryCollection(geometryArray);
     }
+
     /**
      * Given a irregular geojson, with hole the centroid point is still inside the polygon
+     *
      * @throws IOException - Not expected to throw this
      */
     @Test
@@ -58,8 +60,8 @@ public void verifyCentroidCorrect() throws IOException {
 
         List<Coordinate> point = GeometryUtils.calculateCollectionCentroid(convertToGeometryCollection(feature));
         assertEquals(1, point.size(), "One item");
-        assertEquals(2.805438932281021, point.get(0).getX(),"X");
-        assertEquals( 2.0556251797475227, point.get(0).getY(), "Y");
+        assertEquals(2.805438932281021, point.get(0).getX(), "X");
+        assertEquals(2.0556251797475227, point.get(0).getY(), "Y");
     }
 
     @Test
@@ -102,4 +104,18 @@ public void verifyCreateGirdPolygonWithTooBigCellSize() {
         Assertions.assertTrue(gridPolygons.get(0).equalsExact(polygon), "Get back itself");
     }
 
+    @Test
+    public void verifyConvertToWktWithNullGeometry() {
+        // Test with null input
+        String result = GeometryUtils.convertToWkt(null);
+        Assertions.assertNull(result, "Expected null for null input");
+    }
+
+    @Test
+    public void verifyConvertToWktWithNonSpecifiedMultiPolygon() {
+        // Test with NON_SPECIFIED_MULTIPOLYGON constant value
+        String result = GeometryUtils.convertToWkt(GeometryUtils.NON_SPECIFIED_MULTIPOLYGON);
+        Assertions.assertNull(result, "Expected null for non-specified multipolygon");
+    }
+
 }