Minor fixups to some index entries.
diff --git a/Doc/ref/ref7.tex b/Doc/ref/ref7.tex
index 2f0eb33..cacd8ef 100644
--- a/Doc/ref/ref7.tex
+++ b/Doc/ref/ref7.tex
@@ -239,9 +239,10 @@
 their previous values (before the call) when returning from a function
 that handled an exception.
 \refbimodindex{sys}
-\ttindex{exc_type}
-\ttindex{exc_value}
-\ttindex{exc_traceback}
+\withsubitem{(in module sys)}{%
+  \ttindex{exc_type}%
+  \ttindex{exc_value}%
+  \ttindex{exc_traceback}}
 \obindex{traceback}
 
 The optional \keyword{else} clause is executed when no exception occurs