diff --git a/wp-includes/l10n/class-wp-translation-file-mo.php b/wp-includes/l10n/class-wp-translation-file-mo.php
index bf39cc70ec..3f5e72597c 100644
--- a/wp-includes/l10n/class-wp-translation-file-mo.php
+++ b/wp-includes/l10n/class-wp-translation-file-mo.php
@@ -66,11 +66,13 @@ class WP_Translation_File_MO extends WP_Translation_File {
 			return false;
 		}
 
-		if ( self::MAGIC_MARKER === $big ) {
+		// Force cast to an integer as it can be a float on x86 systems. See https://core.trac.wordpress.org/ticket/60678.
+		if ( (int) self::MAGIC_MARKER === $big ) {
 			return 'N';
 		}
 
-		if ( self::MAGIC_MARKER === $little ) {
+		// Force cast to an integer as it can be a float on x86 systems. See https://core.trac.wordpress.org/ticket/60678.
+		if ( (int) self::MAGIC_MARKER === $little ) {
 			return 'V';
 		}
 
@@ -203,7 +205,17 @@ class WP_Translation_File_MO extends WP_Translation_File {
 		$hash_addr         = $translations_addr + $bytes_for_entries;
 		$entry_offsets     = $hash_addr;
 
-		$file_header = pack( $this->uint32 . '*', self::MAGIC_MARKER, 0 /* rev */, $entry_count, $originals_addr, $translations_addr, 0 /* hash_length */, $hash_addr );
+		$file_header = pack(
+			$this->uint32 . '*',
+			// Force cast to an integer as it can be a float on x86 systems. See https://core.trac.wordpress.org/ticket/60678.
+			(int) self::MAGIC_MARKER,
+			0, /* rev */
+			$entry_count,
+			$originals_addr,
+			$translations_addr,
+			0, /* hash_length */
+			$hash_addr
+		);
 
 		$o_entries = '';
 		$t_entries = '';
diff --git a/wp-includes/version.php b/wp-includes/version.php
index a3fb020c15..5a3307ef98 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.5-beta3-57762';
+$wp_version = '6.5-beta3-57763';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.