diff --git a/src/wp-includes/formatting.php b/src/wp-includes/formatting.php
index d170728e01..e618536f41 100644
--- a/src/wp-includes/formatting.php
+++ b/src/wp-includes/formatting.php
@@ -762,8 +762,8 @@ function wp_replace_in_html_tags( $haystack, $replace_pairs ) {
 	// Optimize when searching for one item.
 	if ( 1 === count( $replace_pairs ) ) {
 		// Extract $needle and $replace.
-		foreach ( $replace_pairs as $needle => $replace ) {
-		}
+		$needle  = array_key_first( $replace_pairs );
+		$replace = $replace_pairs[ $needle ];
 
 		// Loop through delimiters (elements) only.
 		for ( $i = 1, $c = count( $textarr ); $i < $c; $i += 2 ) {