Derive the name of the modules .ind from the jobname.
diff --git a/Doc/lib.tex b/Doc/lib.tex
index 537e48c..5e129fb 100644
--- a/Doc/lib.tex
+++ b/Doc/lib.tex
@@ -223,7 +223,7 @@
 \input{libundoc}
 
 \renewcommand{\indexname}{Module Index}
-\input{modules.ind}		% Module Index
+\input{modlib.ind}		% Module Index
 
 \renewcommand{\indexname}{Index}
 \input{lib.ind}			% Index
diff --git a/Doc/lib/lib.tex b/Doc/lib/lib.tex
index 537e48c..5e129fb 100644
--- a/Doc/lib/lib.tex
+++ b/Doc/lib/lib.tex
@@ -223,7 +223,7 @@
 \input{libundoc}
 
 \renewcommand{\indexname}{Module Index}
-\input{modules.ind}		% Module Index
+\input{modlib.ind}		% Module Index
 
 \renewcommand{\indexname}{Index}
 \input{lib.ind}			% Index