diff --git a/SpecialMathShowImage.php b/SpecialMathShowImage.php
index 32f2f08..d919e38 100644
--- a/SpecialMathShowImage.php
+++ b/SpecialMathShowImage.php
@@ -32,7 +32,7 @@ class SpecialMathShowImage extends SpecialPage {
 			$request->response()->header( "Content-type: image/svg+xml; charset=utf-8" );
 		}
 		if ( $success && !( $this->noRender ) ) {
-			$request->response()->header( 'Cache-Control: public max-age=2419200' ); // 4 weeks
+			$request->response()->header( 'Cache-Control: public, s-maxage=604800, max-age=3600' ); // 1 week (server) 1 hour (client)
 			$request->response()->header( 'Vary: User-Agent' );
 		}
 	}