diff -r 0953dec1fcb0 -r b92565f98206 src/Pure/ML/ml_name_space.ML
--- a/src/Pure/ML/ml_name_space.ML	Sat Apr 09 14:40:00 2016 +0200
+++ b/src/Pure/ML/ml_name_space.ML	Sat Apr 09 14:52:10 2016 +0200
@@ -65,9 +65,10 @@
       "chapter", "section", "subsection", "subsubsection", "paragraph", "subparagraph"];
   val hidden_structures = ["CInterface", "Foreign", "RunCall", "RuntimeCalls", "Signal"];
   val bootstrap_structures =
-    ["Exn", "Basic_Exn", "Thread_Data", "ML_Recursive", "PolyML"] @ hidden_structures;
+    ["Exn", "Basic_Exn", "Thread_Data", "Thread_Position", "ML_Recursive", "PolyML"] @
+      hidden_structures;
   val bootstrap_signatures =
-    ["EXN", "BASIC_EXN", "THREAD_DATA", "ML_RECURSIVE"];
+    ["EXN", "BASIC_EXN", "THREAD_DATA", "THREAD_POSITION", "ML_RECURSIVE"];
 
 
   (* Standard ML environment *)