diff --git a/forge-game/src/main/java/forge/game/ability/AbilityUtils.java b/forge-game/src/main/java/forge/game/ability/AbilityUtils.java
index 135a52ea213..db20ea1e4f7 100644
--- a/forge-game/src/main/java/forge/game/ability/AbilityUtils.java
+++ b/forge-game/src/main/java/forge/game/ability/AbilityUtils.java
@@ -1551,7 +1551,7 @@ public class AbilityUtils {
         boolean alreadyPaid = false;
         for (Player payer : allPayers) {
             if (unlessCost.equals("LifeTotalHalfUp")) {
-                String halfup = Integer.toString((int) Math.ceil(payer.getLife() / 2.0));
+                String halfup = Integer.toString(Math.max(0,(int) Math.ceil(payer.getLife() / 2.0)));
                 cost = new Cost("PayLife<" + halfup + ">", true);
             }
             alreadyPaid |= payer.getController().payCostToPreventEffect(cost, sa, alreadyPaid, allPayers);
diff --git a/forge-game/src/main/java/forge/game/cost/CostPayLife.java b/forge-game/src/main/java/forge/game/cost/CostPayLife.java
index 117fba983c3..7953ec78f7e 100644
--- a/forge-game/src/main/java/forge/game/cost/CostPayLife.java
+++ b/forge-game/src/main/java/forge/game/cost/CostPayLife.java
@@ -76,9 +76,13 @@ public class CostPayLife extends CostPart {
         Integer amount = this.convertAmount();
         if (amount == null) { // try to calculate when it's defined.
             amount = AbilityUtils.calculateAmount(ability.getHostCard(), getAmount(), ability);
+            // CR 107.1b
+            if (getAmount().contains("/Half")) {
+                amount = Math.max(amount, 0);
+            }
         }
 
-        if ((amount != null) && !payer.canPayLife(amount)) {
+        if (amount != null && !payer.canPayLife(amount)) {
             return false;
         }
 
diff --git a/forge-game/src/main/java/forge/game/player/Player.java b/forge-game/src/main/java/forge/game/player/Player.java
index b6043d78bbf..454026f3c6c 100644
--- a/forge-game/src/main/java/forge/game/player/Player.java
+++ b/forge-game/src/main/java/forge/game/player/Player.java
@@ -589,7 +589,7 @@ public class Player extends GameEntity implements Comparable<Player> {
     }
 
     public final boolean canPayLife(final int lifePayment) {
-        if (life < lifePayment) {
+        if (lifePayment > 0 && life < lifePayment) {
             return false;
         }
         return (lifePayment <= 0) || !hasKeyword("Your life total can't change.");
diff --git a/forge-gui/src/main/java/forge/player/HumanPlay.java b/forge-gui/src/main/java/forge/player/HumanPlay.java
index 8a76b21a2f3..ba58489a1cf 100644
--- a/forge-gui/src/main/java/forge/player/HumanPlay.java
+++ b/forge-gui/src/main/java/forge/player/HumanPlay.java
@@ -198,8 +198,6 @@ public class HumanPlay {
         req.playAbility(!useOldTargets, false, true);
     }
 
-    // ------------------------------------------------------------------------
-
     private static int getAmountFromPart(CostPart part, Card source, SpellAbility sourceAbility) {
         String amountString = part.getAmount();
         return StringUtils.isNumeric(amountString) ? Integer.parseInt(amountString) : AbilityUtils.calculateAmount(source, amountString, sourceAbility);