diff --git a/src/com/shatteredpixel/shatteredpixeldungeon/items/artifacts/UnstableSpellbook.java b/src/com/shatteredpixel/shatteredpixeldungeon/items/artifacts/UnstableSpellbook.java
index 8527defca..0dd9c0567 100644
--- a/src/com/shatteredpixel/shatteredpixeldungeon/items/artifacts/UnstableSpellbook.java
+++ b/src/com/shatteredpixel/shatteredpixeldungeon/items/artifacts/UnstableSpellbook.java
@@ -180,7 +180,7 @@ public class UnstableSpellbook extends Artifact {
         @Override
         public boolean act() {
             if (charge < chargeCap && !cursed) {
-                partialCharge += 1 / (200f - (chargeCap - charge)*15f);
+                partialCharge += 1 / (150f - (chargeCap - charge)*15f);
 
                 if (partialCharge >= 1) {
                     partialCharge --;