diff --git a/src/wp-includes/load.php b/src/wp-includes/load.php
index 34f30bcb03..7f4a878241 100644
--- a/src/wp-includes/load.php
+++ b/src/wp-includes/load.php
@@ -153,7 +153,11 @@ function wp_check_php_mysql_versions() {
 		exit( 1 );
 	}
 
-	if ( ! extension_loaded( 'mysql' ) && ! extension_loaded( 'mysqli' ) && ! extension_loaded( 'mysqlnd' ) && ! file_exists( WP_CONTENT_DIR . '/db.php' ) ) {
+	if ( ! extension_loaded( 'mysql' ) && ! extension_loaded( 'mysqli' ) && ! extension_loaded( 'mysqlnd' )
+		// This runs before default constants are defined, so we can't assume WP_CONTENT_DIR is set yet.
+		&& ( defined( 'WP_CONTENT_DIR' ) && ! file_exists( WP_CONTENT_DIR . '/db.php' )
+			|| ! file_exists( ABSPATH . 'wp-content/db.php' ) )
+	) {
 		require_once ABSPATH . WPINC . '/functions.php';
 		wp_load_translations_early();
 		$args = array(