diff --git a/Source/spells.cpp b/Source/spells.cpp
index 95e4a1946..95a42dca2 100644
--- a/Source/spells.cpp
+++ b/Source/spells.cpp
@@ -92,19 +92,6 @@ void UseMana(int id, spell_id sn)
 	}
 }
 
-/**
- * @brief Gets a value that represents the specified spellID in 64bit bitmask format.
- * For example:
- *  - spell ID  1: 0000.0000.0000.0000.0000.0000.0000.0000.0000.0000.0000.0000.0000.0000.0000.0001
- *  - spell ID 43: 0000.0000.0000.0000.0000.0100.0000.0000.0000.0000.0000.0000.0000.0000.0000.0000
- * @param spellId The id of the spell to get a bitmask for.
- * @return A 64bit bitmask representation for the specified spell.
- */
-uint64_t GetSpellBitmask(int spellId)
-{
-	return 1ULL << (spellId - 1);
-}
-
 /**
  * @brief Gets a value indicating whether the player's current readied spell is a valid spell. Readied spells can be
  * invalidaded in a few scenarios where the spell comes from items, for example (like dropping the only scroll that
diff --git a/Source/spells.h b/Source/spells.h
index 0488c57d3..8554885d9 100644
--- a/Source/spells.h
+++ b/Source/spells.h
@@ -11,7 +11,6 @@ namespace devilution {
 
 int GetManaAmount(int id, spell_id sn);
 void UseMana(int id, spell_id sn);
-uint64_t GetSpellBitmask(int spellId);
 bool CheckSpell(int id, spell_id sn, spell_type st, bool manaonly);
 void EnsureValidReadiedSpell(PlayerStruct &player);
 void CastSpell(int id, int spl, int sx, int sy, int dx, int dy, int spllvl);
@@ -20,4 +19,17 @@ void DoHealOther(int pnum, int rid);
 int GetSpellBookLevel(spell_id s);
 int GetSpellStaffLevel(spell_id s);
 
+/**
+ * @brief Gets a value that represents the specified spellID in 64bit bitmask format.
+ * For example:
+ *  - spell ID  1: 0000.0000.0000.0000.0000.0000.0000.0000.0000.0000.0000.0000.0000.0000.0000.0001
+ *  - spell ID 43: 0000.0000.0000.0000.0000.0100.0000.0000.0000.0000.0000.0000.0000.0000.0000.0000
+ * @param spellId The id of the spell to get a bitmask for.
+ * @return A 64bit bitmask representation for the specified spell.
+ */
+constexpr uint64_t GetSpellBitmask(int spellId)
+{
+	return 1ULL << (spellId - 1);
+}
+
 } // namespace devilution