diff --git a/src/gammalib-setup.in b/src/gammalib-setup.in
index d473a5c..4551d9a 100644
--- a/src/gammalib-setup.in
+++ b/src/gammalib-setup.in
@@ -148,7 +148,7 @@ fi
 # Set MANPATH
 # ==============
 if [ "x$MANPATH" = x ]; then
-  MANPATH="$man_dir"
+  MANPATH="$man_dir:$(manpath)"
 else
   MANPATH=`echo ":$MANPATH:" | \
     sed "s%:$man_dir:%:%g" | sed "s%::*$%%"`