Index: wp-admin/css/plugin-install.dev.css
===================================================================
--- wp-admin/css/plugin-install.dev.css	(revision 17522)
+++ wp-admin/css/plugin-install.dev.css	(working copy)
@@ -149,4 +149,5 @@
 
 #plugin-information pre {
 	padding: 7px;
+	overflow: auto;
 }