diff --git a/src/wp-includes/comment-template.php b/src/wp-includes/comment-template.php
index 943113605c..e6b246cf14 100644
--- a/src/wp-includes/comment-template.php
+++ b/src/wp-includes/comment-template.php
@@ -2499,7 +2499,7 @@ function comment_form( $args = array(), $post_id = null ) {
 	 */
 	$args = wp_parse_args( $args, apply_filters( 'comment_form_defaults', $defaults ) );
 
-	// Ensure that the filtered args contain all required default values.
+	// Ensure that the filtered arguments contain all required default values.
 	$args = array_merge( $defaults, $args );
 
 	// Remove `aria-describedby` from the email field if there's no associated description.
diff --git a/src/wp-includes/general-template.php b/src/wp-includes/general-template.php
index 15c4974304..94e2d1b97d 100644
--- a/src/wp-includes/general-template.php
+++ b/src/wp-includes/general-template.php
@@ -281,6 +281,9 @@ function get_search_form( $args = array() ) {
 	 */
 	$args = apply_filters( 'search_form_args', $args );
 
+	// Ensure that the filtered arguments contain all required default values.
+	$args = array_merge( $defaults, $args );
+
 	$format = current_theme_supports( 'html5', 'search-form' ) ? 'html5' : 'xhtml';
 
 	/**
@@ -303,7 +306,7 @@ function get_search_form( $args = array() ) {
 		$form = ob_get_clean();
 	} else {
 		// Build a string containing an aria-label to use for the search form.
-		if ( isset( $args['aria_label'] ) && $args['aria_label'] ) {
+		if ( $args['aria_label'] ) {
 			$aria_label = 'aria-label="' . esc_attr( $args['aria_label'] ) . '" ';
 		} else {
 			/*