diff --git a/doc/fixes3-7-0.txt b/doc/fixes3-7-0.txt
index 03f119fee..b2f4651bb 100644
--- a/doc/fixes3-7-0.txt
+++ b/doc/fixes3-7-0.txt
@@ -2024,6 +2024,8 @@ eating a pyrolisk egg on the floor triggered an "object lost" panic
 core object creation and the curses interface's window handling both became
 	confused by the 'pauper' option/conduct because they assumed that invent
 	being Null meant that the game hadn't started yet
+wizards were discovering unread spellbooks whenever any skill was advanced; do so
+	only when a spell skill is advanced
 
 
 Fixes to 3.7.0-x Platform and/or Interface Problems Exposed Via git Repository
diff --git a/src/weapon.c b/src/weapon.c
index d34d9eb89..e10c456fa 100644
--- a/src/weapon.c
+++ b/src/weapon.c
@@ -1148,7 +1148,11 @@ skill_advance(int skill)
         P_SKILL(skill) >= P_MAX_SKILL(skill) ? "most" : "more",
         P_NAME(skill));
 
-    skill_based_spellbook_id();
+    /* wizards discover spellbook IDs depending on spell 'school' skill limits;
+       this allows them to successfully write books for unknown spells without
+       the Luck bias they used to have over other roles */
+    if (skill >= P_FIRST_SPELL && skill <= P_LAST_SPELL)
+        skill_based_spellbook_id();
 }
 
 static const struct skill_range {