diff --git a/forge-game/src/main/java/forge/game/ability/effects/ManaEffect.java b/forge-game/src/main/java/forge/game/ability/effects/ManaEffect.java
index e03f72f8843..5a4521adae4 100644
--- a/forge-game/src/main/java/forge/game/ability/effects/ManaEffect.java
+++ b/forge-game/src/main/java/forge/game/ability/effects/ManaEffect.java
@@ -270,9 +270,14 @@ public class ManaEffect extends SpellAbilityEffect {
                 ? GameActionUtil.generatedMana(sa) : "mana";
         sb.append("Add ").append(toManaString(mana)).append(".");
         if (sa.hasParam("RestrictValid")) {
-            String desc = sa.getDescription();
-            int i = desc.indexOf("Spend this");
-            sb.append(" ").append(desc, i, desc.indexOf(".", i) + 1);
+            sb.append(" ");
+            final String desc = sa.getDescription();
+            if (desc.contains("Spend this") && desc.contains(".")) {
+                int i = desc.indexOf("Spend this");
+                sb.append(desc, i, desc.indexOf(".", i) + 1);
+            } else {
+                sb.append("[failed to add RestrictValid to StackDesc]");
+            }
         }
         return sb.toString();
     }