diff --git a/src/Basic_Requirement_Checker.php b/src/Basic_Requirement_Checker.php
index c99d615f6445a3eeddd7d868807464a29e4dca97..9da3fb523d0fdfdfe8b3b69cc98c44467d74fedf 100644
--- a/src/Basic_Requirement_Checker.php
+++ b/src/Basic_Requirement_Checker.php
@@ -33,6 +33,10 @@ if ( ! class_exists( 'WPDesk_Basic_Requirement_Checker' ) ) {
 
 		const CACHE_TIME = 16;
 
+		const EXPIRATION_TIME = 'expiration_time';
+
+		const PLUGINS = 'plugins';
+
 		/** @var string */
 		protected $plugin_name;
 
@@ -395,10 +399,10 @@ if ( ! class_exists( 'WPDesk_Basic_Requirement_Checker' ) ) {
 				try {
 					$plugins_option_value = json_decode( get_option( self::PLUGIN_INFO_TRANSIENT_NAME . '' ), true );
 					if ( is_array( $plugins_option_value )
-					     && isset( $plugins_option_value['expiration_time'], $plugins_option_value['plugins'] )
-					     && (int) $plugins_option_value['expiration_time'] > $current_time
+					     && isset( $plugins_option_value[ self::EXPIRATION_TIME ], $plugins_option_value[ self::PLUGINS ] )
+					     && (int) $plugins_option_value[ self::EXPIRATION_TIME ] > $current_time
 					) {
-						return $plugins_option_value['plugins'];
+						return $plugins_option_value[ self::PLUGINS ];
 					}
 				} catch ( \RuntimeException $e ) {
 					// Exception can be thrown when option is not json encoded
@@ -419,8 +423,8 @@ if ( ! class_exists( 'WPDesk_Basic_Requirement_Checker' ) ) {
 				set_transient( self::PLUGIN_INFO_TRANSIENT_NAME, $plugins, self::CACHE_TIME );
 			} else {
 				update_option( self::PLUGIN_INFO_TRANSIENT_NAME, json_encode( array(
-					'expiration_time' => $current_time + self::CACHE_TIME,
-					'plugins'         => $plugins,
+					self::EXPIRATION_TIME => $current_time + self::CACHE_TIME,
+					self::PLUGINS         => $plugins,
 				) ) );
 			}