diff --git a/src/wp-admin/js/updates.js b/src/wp-admin/js/updates.js
index 1c15f8d495..9a3dd7646a 100644
--- a/src/wp-admin/js/updates.js
+++ b/src/wp-admin/js/updates.js
@@ -481,7 +481,7 @@ window.wp = window.wp || {};
 			target = window.parent == window ? null : window.parent,
 			$.support.postMessage = !! window.postMessage;
 
-			if ( $.support.postMessage === false || target === null || window.location.search.indexOf( 'parent=update-core' ) !== -1 )
+			if ( $.support.postMessage === false || target === null || window.parent.location.pathname.indexOf( 'update-core.php' ) !== -1 )
 				return;
 
 			e.preventDefault();
diff --git a/src/wp-admin/update-core.php b/src/wp-admin/update-core.php
index 538b7ca3b1..c469120f81 100644
--- a/src/wp-admin/update-core.php
+++ b/src/wp-admin/update-core.php
@@ -264,7 +264,7 @@ function list_plugin_updates() {
 			$upgrade_notice = '';
 		}
 
-		$details_url = self_admin_url('plugin-install.php?tab=plugin-information&parent=update-core&plugin=' . $plugin_data->update->slug . '&section=changelog&TB_iframe=true&width=640&height=662');
+		$details_url = self_admin_url('plugin-install.php?tab=plugin-information&plugin=' . $plugin_data->update->slug . '&section=changelog&TB_iframe=true&width=640&height=662');
 		$details_text = sprintf(__('View version %1$s details'), $plugin_data->update->new_version);
 		$details = sprintf('<a href="%1$s" class="thickbox" title="%2$s">%3$s</a>.', esc_url($details_url), esc_attr($plugin_data->Name), $details_text);