diff --git a/Doc/lib/liboperator.tex b/Doc/lib/liboperator.tex
index d371ee3..d4b7ca9 100644
--- a/Doc/lib/liboperator.tex
+++ b/Doc/lib/liboperator.tex
@@ -1,6 +1,7 @@
 % Contributed by Skip Montanaro, from the module's doc strings.
 
 \section{Built-in Module \sectcode{operator}}
+\label{module-operator}
 \bimodindex{operator}
 
 The \code{operator} module exports a set of functions implemented in C
diff --git a/Doc/lib/libsun.tex b/Doc/lib/libsun.tex
index f6d9994..68d2c8b 100644
--- a/Doc/lib/libsun.tex
+++ b/Doc/lib/libsun.tex
@@ -5,6 +5,7 @@
 latter is also known as Solaris version 2).
 
 \section{Built-in Module \sectcode{sunaudiodev}}
+\label{module-sunaudiodev}
 \bimodindex{sunaudiodev}
 
 This module allows you to access the sun audio interface. The sun
diff --git a/Doc/liboperator.tex b/Doc/liboperator.tex
index d371ee3..d4b7ca9 100644
--- a/Doc/liboperator.tex
+++ b/Doc/liboperator.tex
@@ -1,6 +1,7 @@
 % Contributed by Skip Montanaro, from the module's doc strings.
 
 \section{Built-in Module \sectcode{operator}}
+\label{module-operator}
 \bimodindex{operator}
 
 The \code{operator} module exports a set of functions implemented in C
diff --git a/Doc/libsun.tex b/Doc/libsun.tex
index f6d9994..68d2c8b 100644
--- a/Doc/libsun.tex
+++ b/Doc/libsun.tex
@@ -5,6 +5,7 @@
 latter is also known as Solaris version 2).
 
 \section{Built-in Module \sectcode{sunaudiodev}}
+\label{module-sunaudiodev}
 \bimodindex{sunaudiodev}
 
 This module allows you to access the sun audio interface. The sun