diff --git a/views/bootstrap/class.Bootstrap.php b/views/bootstrap/class.Bootstrap.php
index d86e105ab..279222dba 100644
--- a/views/bootstrap/class.Bootstrap.php
+++ b/views/bootstrap/class.Bootstrap.php
@@ -54,8 +54,9 @@ class SeedDMS_Bootstrap_Style extends SeedDMS_View_Common {
 			 * since version 25+
 			 * X-Content-Security-Policy is deprecated, Firefox understands
 			 * Content-Security-Policy since version 23+
+			 * 'worker-src blob:' is needed for cytoscape
 			 */
-			$csp_rules = "script-src 'self' 'unsafe-eval';"; // style-src 'self';";
+			$csp_rules = "script-src 'self' 'unsafe-eval'; worker-src blob:;"; // style-src 'self';";
 			foreach (array("X-WebKit-CSP", "X-Content-Security-Policy", "Content-Security-Policy") as $csp) {
 				header($csp . ": " . $csp_rules);
 			}