diff --git a/src/pokemon.c b/src/pokemon.c
index d76d1df58c..faa1a65aef 100644
--- a/src/pokemon.c
+++ b/src/pokemon.c
@@ -1800,29 +1800,19 @@ void CalculateMonStats(struct Pokemon *mon)
     CALC_STAT(baseSpAttack, spAttackIV, spAttackEV, STAT_SPATK, MON_DATA_SPATK)
     CALC_STAT(baseSpDefense, spDefenseIV, spDefenseEV, STAT_SPDEF, MON_DATA_SPDEF)
 
-    if (species == SPECIES_SHEDINJA)
-    {
-        if (currentHP != 0 || oldMaxHP == 0)
-            currentHP = 1;
-        else
-            return;
-    }
-    else
-    {
-        if (currentHP == 0 && oldMaxHP == 0)
-            currentHP = newMaxHP;
-        else if (currentHP != 0)
-        {
-            if (newMaxHP > oldMaxHP)
-                currentHP += newMaxHP - oldMaxHP;
-            if (currentHP <= 0)
-                currentHP = 1;
-            if (currentHP > newMaxHP)
-                currentHP = newMaxHP;
-        }
-        else
-            return;
-    }
+    // Since a pokemon's maxHP data could either not have
+    // been initialized at this point or this pokemon is
+    // just fainted, the check for oldMaxHP is important.
+    if (currentHP == 0 && oldMaxHP != 0)
+        return;
+
+    // Only add to currentHP if newMaxHP went up.
+    if (newMaxHP > oldMaxHP)
+        currentHP += newMaxHP - oldMaxHP;
+
+    // Ensure currentHP does not surpass newMaxHP.
+    if (currentHP > newMaxHP)
+        currentHP = newMaxHP;
 
     SetMonData(mon, MON_DATA_HP, &currentHP);
 }