diff --git a/wp-admin/includes/plugin.php b/wp-admin/includes/plugin.php
index 69da5dba9c..3767609bab 100644
--- a/wp-admin/includes/plugin.php
+++ b/wp-admin/includes/plugin.php
@@ -1095,28 +1095,11 @@ function validate_plugin( $plugin ) {
  * @return true|WP_Error True if requirements are met, WP_Error on failure.
  */
 function validate_plugin_requirements( $plugin ) {
-	$readme_file = WP_PLUGIN_DIR . '/' . dirname( $plugin ) . '/readme.txt';
-	$plugin_data = array(
-		'requires'     => '',
-		'requires_php' => '',
-	);
-
-	if ( file_exists( $readme_file ) ) {
-		$plugin_data = get_file_data(
-			$readme_file,
-			array(
-				'requires'     => 'Requires at least',
-				'requires_php' => 'Requires PHP',
-			),
-			'plugin'
-		);
-	}
-
-	$plugin_data = array_merge( $plugin_data, get_plugin_data( WP_PLUGIN_DIR . '/' . $plugin ) );
+	$plugin_data = get_plugin_data( WP_PLUGIN_DIR . '/' . $plugin );
 
-	// Check for headers in the plugin's PHP file, give precedence to the plugin headers.
-	$plugin_data['requires']     = ! empty( $plugin_data['RequiresWP'] ) ? $plugin_data['RequiresWP'] : $plugin_data['requires'];
-	$plugin_data['requires_php'] = ! empty( $plugin_data['RequiresPHP'] ) ? $plugin_data['RequiresPHP'] : $plugin_data['requires_php'];
+	// Check for headers in the main plugin file.
+	$plugin_data['requires']     = ! empty( $plugin_data['Requires'] ) ? $plugin_data['Requires'] : '';
+	$plugin_data['requires_php'] = ! empty( $plugin_data['RequiresPHP'] ) ? $plugin_data['RequiresPHP'] : '';
 
 	$plugin_data['wp_compatible']  = is_wp_version_compatible( $plugin_data['requires'] );
 	$plugin_data['php_compatible'] = is_php_version_compatible( $plugin_data['requires_php'] );