diff --git a/classes/Optimization/Process/AbstractProcess.php b/classes/Optimization/Process/AbstractProcess.php
index bec0948df..4c6148f6d 100644
--- a/classes/Optimization/Process/AbstractProcess.php
+++ b/classes/Optimization/Process/AbstractProcess.php
@@ -259,7 +259,7 @@ public function optimize( $optimization_level = null, $args = [] ) {
 		if ( $data->is_already_optimized() && $this->has_webp() ) {
 			// If already optimized but has WebP, delete WebP versions and optimization data.
 			$data->delete_optimization_data();
-			$deleted = $this->delete_webp_files();
+			$deleted = $this->delete_nextgen_files();
 
 			if ( is_wp_error( $deleted ) ) {
 				return new WP_Error( 'webp_not_deleted', __( 'Previous WebP files could not be deleted.', 'imagify' ) );
@@ -935,7 +935,7 @@ protected function restore_thumbnails() {
 		 * In that case we must also delete the WebP file associated to the full size.
 		 */
 		$keep_full_webp = $media->get_raw_original_path() === $media->get_raw_fullsize_path();
-		$this->delete_webp_files( $keep_full_webp );
+		$this->delete_nextgen_files( $keep_full_webp );
 
 		// Generate new thumbnails.
 		return $media->generate_thumbnails();
@@ -1321,7 +1321,7 @@ protected function can_backup( $size ) {
 	 *
 	 * @return bool|WP_Error True if successfully launched. A \WP_Error instance on failure.
 	 */
-	public function generate_webp_versions() {
+	public function generate_nextgen_versions() {
 		if ( ! $this->is_valid() ) {
 			return new WP_Error( 'invalid_media', __( 'This media is not valid.', 'imagify' ) );
 		}
@@ -1349,7 +1349,7 @@ public function generate_webp_versions() {
 		$files = $media->get_media_files();
 		$sizes = [];
 		$args  = [
-			'hook_suffix' => 'generate_webp_versions',
+			'hook_suffix' => 'generate_nextgen_versions',
 		];
 
 		foreach ( $files as $size_name => $file ) {
@@ -1378,7 +1378,7 @@ public function generate_webp_versions() {
 	 * @param  bool $keep_full Set to true to keep the full size.
 	 * @return bool|WP_Error  True on success. A \WP_Error object on failure.
 	 */
-	public function delete_webp_files( $keep_full = false ) {
+	public function delete_nextgen_files( $keep_full = false ) {
 		if ( ! $this->is_valid() ) {
 			return new WP_Error( 'invalid_media', __( 'This media is not valid.', 'imagify' ) );
 		}
diff --git a/classes/Optimization/Process/Noop.php b/classes/Optimization/Process/Noop.php
index 06a18aab8..bc168bd66 100644
--- a/classes/Optimization/Process/Noop.php
+++ b/classes/Optimization/Process/Noop.php
@@ -287,7 +287,7 @@ public function maybe_resize( $size, $file ) {
 	/** ----------------------------------------------------------------------------------------- */
 
 	/**
-	 * Generate WebP images if they are missing.
+	 * Generate Nextgen images if they are missing.
 	 *
 	 * @since  1.9
 	 * @access public
@@ -295,7 +295,7 @@ public function maybe_resize( $size, $file ) {
 	 *
 	 * @return bool|WP_Error True if successfully launched. A \WP_Error instance on failure.
 	 */
-	public function generate_webp_versions() {
+	public function generate_nextgen_versions() {
 		return new \WP_Error( 'invalid_media', __( 'This media is not valid.', 'imagify' ) );
 	}
 
@@ -306,7 +306,7 @@ public function generate_webp_versions() {
 	 * @access public
 	 * @author Grégory Viguier
 	 */
-	public function delete_webp_files() {}
+	public function delete_nextgen_files() {}
 
 	/**
 	 * Tell if a thumbnail size is an "Imagify WebP" size.
diff --git a/classes/Optimization/Process/ProcessInterface.php b/classes/Optimization/Process/ProcessInterface.php
index fa525647f..66bd00ca3 100644
--- a/classes/Optimization/Process/ProcessInterface.php
+++ b/classes/Optimization/Process/ProcessInterface.php
@@ -246,7 +246,7 @@ public function maybe_resize( $size, $file );
 	 *
 	 * @return bool|WP_Error True if successfully launched. A \WP_Error instance on failure.
 	 */
-	public function generate_webp_versions();
+	public function generate_nextgen_versions();
 
 	/**
 	 * Delete the WebP images.
@@ -260,7 +260,7 @@ public function generate_webp_versions();
 	 * @param  bool $keep_full Set to true to keep the full size.
 	 * @return bool|\WP_Error  True on success. A \WP_Error object on failure.
 	 */
-	public function delete_webp_files( $keep_full = false );
+	public function delete_nextgen_files( $keep_full = false );
 
 	/**
 	 * Tell if a thumbnail size is an "Imagify WebP" size.
diff --git a/inc/3rd-party/nextgen-gallery/inc/common/attachments.php b/inc/3rd-party/nextgen-gallery/inc/common/attachments.php
index 183812061..05e452140 100644
--- a/inc/3rd-party/nextgen-gallery/inc/common/attachments.php
+++ b/inc/3rd-party/nextgen-gallery/inc/common/attachments.php
@@ -284,7 +284,7 @@ function imagify_ngg_cleanup_after_media_deletion( $image_id, $image ) {
 	 * The backup file has already been deleted by NGG.
 	 * Delete the WebP versions and the optimization data.
 	 */
-	$process->delete_webp_files();
+	$process->delete_nextgen_files();
 	$process->get_data()->delete_optimization_data();
 }
 
diff --git a/inc/classes/class-imagify-admin-ajax-post.php b/inc/classes/class-imagify-admin-ajax-post.php
index b288d39f0..c799457bd 100755
--- a/inc/classes/class-imagify-admin-ajax-post.php
+++ b/inc/classes/class-imagify-admin-ajax-post.php
@@ -203,7 +203,7 @@ protected function optimize_missing_sizes( $media_id, $context ) {
 	 * @return bool|WP_Error    True if successfully launched. A \WP_Error instance on failure.
 	 */
 	protected function generate_nextgen_versions( $media_id, $context ) {
-		return imagify_get_optimization_process( $media_id, $context )->generate_webp_versions();
+		return imagify_get_optimization_process( $media_id, $context )->generate_nextgen_versions();
 	}
 
 	/**
@@ -233,7 +233,7 @@ protected function delete_nextgen_versions( $media_id, $context ) {
 		}
 
 		$data->delete_optimization_data();
-		$deleted = $process->delete_webp_files();
+		$deleted = $process->delete_nextgen_files();
 
 		if ( is_wp_error( $deleted ) ) {
 			return new WP_Error( 'webp_not_deleted', __( 'Previous WebP files could not be deleted.', 'imagify' ) );
diff --git a/inc/common/attachments.php b/inc/common/attachments.php
index b58f070e7..982790658 100755
--- a/inc/common/attachments.php
+++ b/inc/common/attachments.php
@@ -36,9 +36,9 @@ function imagify_cleanup_after_media_deletion( $process ) {
 
 	/**
 	 * The optimization data will be automatically deleted by WP (post metas).
-	 * Delete the WebP versions and the backup file.
+	 * Delete the Nextgen versions and the backup file.
 	 */
-	$process->delete_webp_files();
+	$process->delete_nextgen_files();
 	$process->delete_backup();
 }