diff --git a/wp-includes/general-template.php b/wp-includes/general-template.php
index 8655ceed21..b1abd3f0e6 100644
--- a/wp-includes/general-template.php
+++ b/wp-includes/general-template.php
@@ -2587,20 +2587,18 @@ function language_attributes($doctype = 'html') {
 function paginate_links( $args = '' ) {
 	global $wp_query, $wp_rewrite;
 
-	$total        = ( isset( $wp_query->max_num_pages ) ) ? $wp_query->max_num_pages : 1;
-	$current      = ( get_query_var( 'paged' ) ) ? intval( get_query_var( 'paged' ) ) : 1;
+	// Setting up default values based on the current URL.
 	$pagenum_link = html_entity_decode( get_pagenum_link() );
-	$query_args   = array();
 	$url_parts    = explode( '?', $pagenum_link );
 
-	if ( isset( $url_parts[1] ) ) {
-		wp_parse_str( $url_parts[1], $query_args );
-		$query_args = urlencode_deep( $query_args );
-	}
+	// Get max pages and current page out of the current query, if available.
+	$total   = isset( $wp_query->max_num_pages ) ? $wp_query->max_num_pages : 1;
+	$current = get_query_var( 'paged' ) ? intval( get_query_var( 'paged' ) ) : 1;
 
-	$pagenum_link = remove_query_arg( array_keys( $query_args ), $pagenum_link );
-	$pagenum_link = trailingslashit( $pagenum_link ) . '%_%';
+	// Append the format placeholder to the base URL.
+	$pagenum_link = trailingslashit( $url_parts[0] ) . '%_%';
 
+	// URL base depends on permalink settings.
 	$format  = $wp_rewrite->using_index_permalinks() && ! strpos( $pagenum_link, 'index.php' ) ? 'index.php/' : '';
 	$format .= $wp_rewrite->using_permalinks() ? user_trailingslashit( $wp_rewrite->pagination_base . '/%#%', 'paged' ) : '?paged=%#%';
 
@@ -2616,7 +2614,7 @@ function paginate_links( $args = '' ) {
 		'end_size' => 1,
 		'mid_size' => 2,
 		'type' => 'plain',
-		'add_args' => $query_args, // array of query args to add
+		'add_args' => array(), // array of query args to add
 		'add_fragment' => '',
 		'before_page_number' => '',
 		'after_page_number' => ''
@@ -2624,6 +2622,21 @@ function paginate_links( $args = '' ) {
 
 	$args = wp_parse_args( $args, $defaults );
 
+	if ( ! is_array( $args['add_args'] ) ) {
+		$args['add_args'] = array();
+	}
+
+	// Merge additional query vars found in the original URL into 'add_args' array.
+	if ( isset( $url_parts[1] ) ) {
+		// Find the format argument.
+		$format_query = parse_url( str_replace( '%_%', $args['format'], $args['base'] ), PHP_URL_QUERY );
+		wp_parse_str( $format_query, $format_arg );
+
+		// Remove the format argument from the array of query arguments, to avoid overwriting custom format.
+		wp_parse_str( remove_query_arg( array_keys( $format_arg ), $url_parts[1] ), $query_args );
+		$args['add_args'] = array_merge( $args['add_args'], urlencode_deep( $query_args ) );
+	}
+
 	// Who knows what else people pass in $args
 	$total = (int) $args['total'];
 	if ( $total < 2 ) {
@@ -2638,7 +2651,7 @@ function paginate_links( $args = '' ) {
 	if ( $mid_size < 0 ) {
 		$mid_size = 2;
 	}
-	$add_args = is_array( $args['add_args'] ) ? $args['add_args'] : false;
+	$add_args = $args['add_args'];
 	$r = '';
 	$page_links = array();
 	$dots = false;