diff --git a/src/dataset.rs b/src/dataset.rs
index c6f99df0..3ef59d24 100644
--- a/src/dataset.rs
+++ b/src/dataset.rs
@@ -567,7 +567,7 @@ impl Dataset {
     ///
     /// let ds = Dataset::open(Path::new("fixtures/roads.geojson")).unwrap();
     /// let query = "SELECT kind, is_bridge, highway FROM roads WHERE highway = 'pedestrian'";
-    /// let result_set = ds.execute_sql(query, None, sql::Dialect::DEFAULT).unwrap().unwrap();
+    /// let mut result_set = ds.execute_sql(query, None, sql::Dialect::DEFAULT).unwrap().unwrap();
     ///
     /// assert_eq!(10, result_set.feature_count());
     ///
diff --git a/src/vector/sql.rs b/src/vector/sql.rs
index decd23d5..ef7d717d 100644
--- a/src/vector/sql.rs
+++ b/src/vector/sql.rs
@@ -1,4 +1,4 @@
-use std::ops::Deref;
+use std::ops::{Deref, DerefMut};
 
 use gdal_sys::GDALDatasetH;
 
@@ -21,6 +21,12 @@ impl<'a> Deref for ResultSet<'a> {
     }
 }
 
+impl<'a> DerefMut for ResultSet<'a> {
+    fn deref_mut(&mut self) -> &mut <Self as Deref>::Target {
+        &mut self.layer
+    }
+}
+
 impl<'a> Drop for ResultSet<'a> {
     fn drop(&mut self) {
         unsafe { gdal_sys::GDALDatasetReleaseResultSet(self.dataset, self.layer.c_layer()) };
diff --git a/src/vector/vector_tests/mod.rs b/src/vector/vector_tests/mod.rs
index b6845135..2231a13f 100644
--- a/src/vector/vector_tests/mod.rs
+++ b/src/vector/vector_tests/mod.rs
@@ -67,7 +67,7 @@ fn test_layer_spatial_ref() {
 
 #[test]
 fn test_layer_capabilities() {
-    let mut ds = Dataset::open(fixture!("roads.geojson")).unwrap();
+    let ds = Dataset::open(fixture!("roads.geojson")).unwrap();
     let layer = ds.layer(0).unwrap();
 
     assert!(!layer.has_capability(OLCFastSpatialFilter));
diff --git a/src/vector/vector_tests/sql.rs b/src/vector/vector_tests/sql.rs
index 82fffc51..34e0d198 100644
--- a/src/vector/vector_tests/sql.rs
+++ b/src/vector/vector_tests/sql.rs
@@ -10,7 +10,7 @@ use crate::{
 fn test_sql() {
     let ds = Dataset::open(fixture!("roads.geojson")).unwrap();
     let query = "SELECT kind, is_bridge, highway FROM roads WHERE highway = 'pedestrian'";
-    let result_set = ds
+    let mut result_set = ds
         .execute_sql(query, None, sql::Dialect::DEFAULT)
         .unwrap()
         .unwrap();
@@ -46,7 +46,7 @@ fn test_sql_with_spatial_filter() {
     let query = "SELECT * FROM roads WHERE highway = 'pedestrian'";
     let ds = Dataset::open(fixture!("roads.geojson")).unwrap();
     let bbox = Geometry::bbox(26.1017, 44.4297, 26.1025, 44.4303).unwrap();
-    let result_set = ds
+    let mut result_set = ds
         .execute_sql(query, Some(&bbox), sql::Dialect::DEFAULT)
         .unwrap()
         .unwrap();
@@ -77,7 +77,7 @@ fn test_sql_with_dialect() {
     let query = "SELECT * FROM roads WHERE highway = 'pedestrian' and NumPoints(GEOMETRY) = 3";
     let ds = Dataset::open(fixture!("roads.geojson")).unwrap();
     let bbox = Geometry::bbox(26.1017, 44.4297, 26.1025, 44.4303).unwrap();
-    let result_set = ds
+    let mut result_set = ds
         .execute_sql(query, Some(&bbox), sql::Dialect::SQLITE)
         .unwrap()
         .unwrap();
@@ -99,7 +99,7 @@ fn test_sql_with_dialect() {
 fn test_sql_empty_result() {
     let ds = Dataset::open(fixture!("roads.geojson")).unwrap();
     let query = "SELECT kind, is_bridge, highway FROM roads WHERE highway = 'jazz hands 👐'";
-    let result_set = ds
+    let mut result_set = ds
         .execute_sql(query, None, sql::Dialect::DEFAULT)
         .unwrap()
         .unwrap();