diff --git a/php/datasource/class-fieldmanager-datasource-post.php b/php/datasource/class-fieldmanager-datasource-post.php
index 0a343cbe19..ad6f1fe951 100644
--- a/php/datasource/class-fieldmanager-datasource-post.php
+++ b/php/datasource/class-fieldmanager-datasource-post.php
@@ -236,12 +236,16 @@ public function presave_alter_values( Fieldmanager_Field $field, $values, $curre
 	 * @return string
 	 */
 	public function presave( Fieldmanager_Field $field, $value, $current_value ) {
-		if ( empty( $value ) ) {
+		if ( $this->only_save_to_post_parent ) {
+			$current_value = $this->preload_alter_values( $field, $current_value );
+		}
+
+		if ( empty( $value ) && empty( $current_value ) ) {
 			return;
 		}
 		$value = intval( $value );
 
-		if ( ! empty( $this->publish_with_parent ) || ! empty( $this->reciprocal ) ) {
+		if ( ! empty( $value ) && ( ! empty( $this->publish_with_parent ) || ! empty( $this->reciprocal ) ) ) {
 			// There are no permissions in cron, but no changes are coming from a user either.
 			if ( ! defined( 'DOING_CRON' ) || ! DOING_CRON ) {
 				$post_type_obj = get_post_type_object( get_post_type( $value ) );
diff --git a/tests/php/test-fieldmanager-datasource-post.php b/tests/php/test-fieldmanager-datasource-post.php
index 1ea406f1af..5759e40c38 100644
--- a/tests/php/test-fieldmanager-datasource-post.php
+++ b/tests/php/test-fieldmanager-datasource-post.php
@@ -368,6 +368,7 @@ public function test_post_parent_nested() {
 			$html
 		);
 	}
+
 	/**
 	 * Test save_to_post_parent_only logic
 	 */
@@ -556,4 +557,31 @@ public function test_inherited_repeatable_post_parent_invalid() {
 			)
 		);
 	}
+
+	/**
+	 * Test save_to_post_parent_only logic
+	 */
+	public function test_unsetting_post_parent_only() {
+		$fm = new Fieldmanager_Autocomplete(
+			array(
+				'name'       => 'test_parent',
+				'datasource' => new Fieldmanager_Datasource_Post(
+					array(
+						'only_save_to_post_parent' => true,
+						'query_args'               => array(
+							'post_type' => 'post',
+						),
+					)
+				),
+			)
+		);
+
+		$this->save_values( $fm, $this->child_post_a, $this->parent_post->ID );
+		$child = get_post( $this->child_post_a->ID );
+		$this->assertEquals( $this->parent_post->ID, $child->post_parent );
+
+		$this->save_values( $fm, $this->child_post_a, '' );
+		$child = get_post( $this->child_post_a->ID );
+		$this->assertEquals( null, $child->post_parent );
+	}
 }