diff -r 909dcdec2122 -r dea94b1aabc3 src/Pure/ML_Bootstrap.thy
--- a/src/Pure/ML_Bootstrap.thy	Wed Dec 06 15:46:35 2017 +0100
+++ b/src/Pure/ML_Bootstrap.thy	Wed Dec 06 18:59:33 2017 +0100
@@ -34,7 +34,7 @@
     \<close>
 \<close>
 
-ML \<open>@{assert} (not (can ML \<open>open RunCall\<close>))\<close>
+ML \<open>\<^assert> (not (can ML \<open>open RunCall\<close>))\<close>
 
 
 subsection \<open>Switch to bootstrap environment\<close>