diff --git a/doc/src/fix_ti_spring.txt b/doc/src/fix_ti_spring.txt
index 40e595e21e41d4a901d9d2afd78e97d771413371..afb1dcf8fffe855b41ac19f62e6504afd8b13540 100644
--- a/doc/src/fix_ti_spring.txt
+++ b/doc/src/fix_ti_spring.txt
@@ -144,7 +144,11 @@ this fix.
 
 "fix spring"_fix_spring.html, "fix adapt"_fix_adapt.html
 
-[Restrictions:] none
+[Restrictions:]
+
+This fix is part of the USER-MISC package. It is only enabled if
+LAMMPS was built with that package. See the "Making
+LAMMPS"_Section_start.html#start_3 section for more info.
 
 [Default:]