diff --git a/python/sedonadb/tests/functions/test_transforms.py b/python/sedonadb/tests/functions/test_transforms.py
index 3a5f8cc71..1e11ecf95 100644
--- a/python/sedonadb/tests/functions/test_transforms.py
+++ b/python/sedonadb/tests/functions/test_transforms.py
@@ -15,7 +15,8 @@
 # specific language governing permissions and limitations
 # under the License.
 import pytest
-from sedonadb.testing import PostGIS, SedonaDB
+import pyproj
+from sedonadb.testing import geom_or_null, PostGIS, SedonaDB, val_or_null
 
 
 @pytest.mark.parametrize("eng", [SedonaDB, PostGIS])
@@ -26,3 +27,42 @@ def test_st_transform(eng):
         "POINT (111319.490793274 111325.142866385)",
         wkt_precision=9,
     )
+
+
+@pytest.mark.parametrize("eng", [SedonaDB, PostGIS])
+@pytest.mark.parametrize(
+    ("geom", "srid", "expected_srid"),
+    [
+        ("POINT (1 1)", None, None),
+        ("POINT (1 1)", 3857, 3857),
+        ("POINT (1 1)", 0, None),
+    ],
+)
+def test_st_setsrid(eng, geom, srid, expected_srid):
+    eng = eng.create_or_skip()
+    result = eng.execute_and_collect(
+        f"SELECT ST_SetSrid({geom_or_null(geom)}, {val_or_null(srid)})"
+    )
+    df = eng.result_to_pandas(result)
+    if expected_srid is None:
+        assert df.crs is None
+    else:
+        assert df.crs == pyproj.CRS(expected_srid)
+
+
+# PostGIS does not handle String CRS input to ST_SetSrid
+@pytest.mark.parametrize("eng", [SedonaDB])
+@pytest.mark.parametrize(
+    ("geom", "srid", "expected_srid"),
+    [
+        ("POINT (1 1)", "EPSG:26920", 26920),
+        ("POINT (1 1)", pyproj.CRS("EPSG:26920").to_json(), 26920),
+    ],
+)
+def test_st_setsrid_sedonadb(eng, geom, srid, expected_srid):
+    eng = eng.create_or_skip()
+    result = eng.execute_and_collect(
+        f"SELECT ST_SetSrid({geom_or_null(geom)}, '{srid}')"
+    )
+    df = eng.result_to_pandas(result)
+    assert df.crs.to_epsg() == expected_srid
diff --git a/rust/sedona-functions/src/st_setsrid.rs b/rust/sedona-functions/src/st_setsrid.rs
index f559fbf35..d02a0f3f7 100644
--- a/rust/sedona-functions/src/st_setsrid.rs
+++ b/rust/sedona-functions/src/st_setsrid.rs
@@ -88,8 +88,12 @@ impl SedonaScalarKernel for STSetSRID {
             if let ScalarValue::Utf8(maybe_crs) = scalar_crs.cast_to(&DataType::Utf8)? {
                 let new_crs = match maybe_crs {
                     Some(crs) => {
-                        validate_crs(&crs, self.engine.as_ref())?;
-                        deserialize_crs(&serde_json::Value::String(crs))?
+                        if crs == "0" {
+                            None
+                        } else {
+                            validate_crs(&crs, self.engine.as_ref())?;
+                            deserialize_crs(&serde_json::Value::String(crs))?
+                        }
                     }
                     None => None,
                 };
@@ -173,6 +177,7 @@ mod test {
         let good_crs_scalar = ScalarValue::Utf8(Some("EPSG:4326".to_string()));
         let null_crs_scalar = ScalarValue::Utf8(None);
         let epsg_code_scalar = ScalarValue::Int32(Some(4326));
+        let unset_scalar = ScalarValue::Int32(Some(0));
         let questionable_crs_scalar = ScalarValue::Utf8(Some("gazornenplat".to_string()));
 
         // Call with a string scalar destination
@@ -193,6 +198,12 @@ mod test {
         assert_eq!(return_type, wkb_lnglat);
         assert_value_equal(&result, &geom_lnglat);
 
+        // Call with an integer code of 0 (should unset the output crs)
+        let (return_type, result) =
+            call_udf(&udf, geom_lnglat.clone(), unset_scalar.clone()).unwrap();
+        assert_eq!(return_type, WKB_GEOMETRY);
+        assert_value_equal(&result, &geom_arg);
+
         // Ensure that an engine can reject a CRS if the UDF was constructed with one
         let udf_with_validation: ScalarUDF =
             st_set_srid_with_engine_udf(Some(Arc::new(ExtremelyUnusefulEngine {}))).into();