diff --git a/core/src/mindustry/entities/bullet/BulletType.java b/core/src/mindustry/entities/bullet/BulletType.java
index 3c774dde32..6c0da0435a 100644
--- a/core/src/mindustry/entities/bullet/BulletType.java
+++ b/core/src/mindustry/entities/bullet/BulletType.java
@@ -161,6 +161,8 @@ public class BulletType extends Content implements Cloneable{
     public float healPercent = 0f;
     /** flat amount of block health healed */
     public float healAmount = 0f;
+    /** Fraction of bullet damage that heals that shooter. */
+    public float lifesteal = 0f;
     /** Whether to make fire on impact */
     public boolean makeFire = false;
     /** Whether this bullet will always hit blocks under it. */
@@ -450,6 +452,10 @@ public class BulletType extends Content implements Cloneable{
             }else{
                 health += shield;
             }
+            if(lifesteal > 0f && b.owner instanceof Healthc o){
+                float result = Math.max(Math.min(h.health(), damage), 0);
+                o.heal(result * lifesteal);
+            }
             if(pierceArmor){
                 h.damagePierce(damage);
             }else{
diff --git a/core/src/mindustry/logic/LAssembler.java b/core/src/mindustry/logic/LAssembler.java
index 2d6b214386..4995bb7e89 100644
--- a/core/src/mindustry/logic/LAssembler.java
+++ b/core/src/mindustry/logic/LAssembler.java
@@ -35,7 +35,7 @@ public class LAssembler{
         Seq<LStatement> st = read(data, privileged);
 
         asm.privileged = privileged;
-        
+
         asm.instructions = st.map(l -> l.build(asm)).retainAll(l -> l != null).toArray(LInstruction.class);
         return asm;
     }
@@ -74,7 +74,7 @@ public class LAssembler{
         symbol = symbol.replace(' ', '_');
 
         //use a positive invalid number if number might be negative, else use a negative invalid number
-        int usedInvalidNum = symbol.startsWith("-") ? invalidNumPositive : invalidNumNegative;
+        int usedInvalidNum = symbol.length() > 0 && symbol.charAt(0) == '-' ? invalidNumPositive : invalidNumNegative;
         double value = parseDouble(symbol, usedInvalidNum);
 
         if(value == usedInvalidNum){