diff --git a/src/wp-includes/comment.php b/src/wp-includes/comment.php
index 80f30e2a8a..ccd8464c51 100644
--- a/src/wp-includes/comment.php
+++ b/src/wp-includes/comment.php
@@ -482,10 +482,6 @@ class WP_Comment_Query {
 		$this->meta_query = new WP_Meta_Query();
 		$this->meta_query->parse_query_vars( $this->query_vars );
 
-		if ( ! empty( $this->meta_query->queries ) ) {
-			$meta_query_clauses = $this->meta_query->get_sql( 'comment', $wpdb->comments, 'comment_ID', $this );
-		}
-
 		/**
 		 * Fires before comments are retrieved.
 		 *
@@ -495,6 +491,12 @@ class WP_Comment_Query {
 		 */
 		do_action_ref_array( 'pre_get_comments', array( &$this ) );
 
+		// Reparse query vars, in case they were modified in a 'pre_get_comments' callback.
+		$this->meta_query->parse_query_vars( $this->query_vars );
+		if ( ! empty( $this->meta_query->queries ) ) {
+			$meta_query_clauses = $this->meta_query->get_sql( 'comment', $wpdb->comments, 'comment_ID', $this );
+		}
+
 		// $args can include anything. Only use the args defined in the query_var_defaults to compute the key.
 		$key = md5( serialize( wp_array_slice_assoc( $this->query_vars, array_keys( $this->query_var_defaults ) ) ) );
 		$last_changed = wp_cache_get( 'last_changed', 'comment' );
diff --git a/tests/phpunit/tests/comment/query.php b/tests/phpunit/tests/comment/query.php
index 0d7269c8f0..420d8f2dad 100644
--- a/tests/phpunit/tests/comment/query.php
+++ b/tests/phpunit/tests/comment/query.php
@@ -1679,4 +1679,62 @@ class Tests_Comment_Query extends WP_UnitTestCase {
 
 		$this->assertSame( $num_queries, $wpdb->num_queries );
 	}
+
+	/**
+	 * @ticket 32762
+	 */
+	public function test_it_should_be_possible_to_modify_meta_query_using_pre_get_comments_action() {
+		$comments = $this->factory->comment->create_many( 2, array(
+			'comment_post_ID' => $this->post_id,
+		) );
+
+		add_comment_meta( $comments[1], 'foo', 'bar' );
+
+		add_action( 'pre_get_comments', array( $this, 'modify_meta_query' ) );
+
+		$q = new WP_Comment_Query( array(
+			'comment_post_ID' => $this->post_id,
+			'fields' => 'ids',
+		) );
+
+		remove_action( 'pre_get_comments', array( $this, 'modify_meta_query' ) );
+
+		$this->assertEqualSets( array( $comments[1] ), $q->comments );
+	}
+
+	public function modify_meta_query( $q ) {
+		$q->meta_query = new WP_Meta_Query( array(
+			array(
+				'key' => 'foo',
+				'value' => 'bar',
+			),
+		) );
+	}
+
+	/**
+	 * @ticket 32762
+	 */
+	public function test_it_should_be_possible_to_modify_meta_params_using_pre_get_comments_action() {
+		$comments = $this->factory->comment->create_many( 2, array(
+			'comment_post_ID' => $this->post_id,
+		) );
+
+		add_comment_meta( $comments[1], 'foo', 'bar' );
+
+		add_action( 'pre_get_comments', array( $this, 'modify_meta_params' ) );
+
+		$q = new WP_Comment_Query( array(
+			'comment_post_ID' => $this->post_id,
+			'fields' => 'ids',
+		) );
+
+		remove_action( 'pre_get_comments', array( $this, 'modify_meta_params' ) );
+
+		$this->assertEqualSets( array( $comments[1] ), $q->comments );
+	}
+
+	public function modify_meta_params( $q ) {
+		$q->query_vars['meta_key'] = 'foo';
+		$q->query_vars['meta_value'] = 'bar';
+	}
 }