diff --git a/bukkit/src/main/java/me/lucko/luckperms/bukkit/migration/MigrationGroupManager.java b/bukkit/src/main/java/me/lucko/luckperms/bukkit/migration/MigrationGroupManager.java
index 63d6af438..2029ceb8b 100644
--- a/bukkit/src/main/java/me/lucko/luckperms/bukkit/migration/MigrationGroupManager.java
+++ b/bukkit/src/main/java/me/lucko/luckperms/bukkit/migration/MigrationGroupManager.java
@@ -86,7 +86,7 @@ public class MigrationGroupManager extends SubCommand<Object> {
             return CommandResult.STATE_ERROR;
         }
         final boolean migrateAsGlobal = Boolean.parseBoolean(args.get(0));
-        final Function<String, String> worldMappingFunc = s -> migrateAsGlobal ? null : s;
+        final Function<String, String> worldMappingFunc = s -> migrateAsGlobal || s == null ? "global" : s;
         
         if (!Bukkit.getPluginManager().isPluginEnabled("GroupManager")) {
             log.logError("Plugin not loaded.");
@@ -145,7 +145,7 @@ public class MigrationGroupManager extends SubCommand<Object> {
                 }
                 for (String s : group.getInherits()) {
                     if (s.isEmpty()) continue;
-                    groups.get(groupName).add(Inheritance.builder(MigrationUtils.standardizeName(s)).value(true).withContext(DefaultContextKeys.SERVER_KEY, null).withContext(DefaultContextKeys.WORLD_KEY, worldMappingFunc.apply(world)).build());
+                    groups.get(groupName).add(Inheritance.builder(MigrationUtils.standardizeName(s)).value(true).withContext(DefaultContextKeys.WORLD_KEY, worldMappingFunc.apply(world)).build());
                 }
 
                 String[] metaKeys = group.getVariables().getVarKeyList();
diff --git a/bukkit/src/main/java/me/lucko/luckperms/bukkit/migration/MigrationPermissionsEx.java b/bukkit/src/main/java/me/lucko/luckperms/bukkit/migration/MigrationPermissionsEx.java
index b33a7ca3f..b65e68fc4 100644
--- a/bukkit/src/main/java/me/lucko/luckperms/bukkit/migration/MigrationPermissionsEx.java
+++ b/bukkit/src/main/java/me/lucko/luckperms/bukkit/migration/MigrationPermissionsEx.java
@@ -313,12 +313,9 @@ public class MigrationPermissionsEx extends SubCommand<Object> {
     }
 
     private static String standardizeWorld(String world) {
-        if (world != null && (world.isEmpty() || world.equals("*"))) {
-            world = null;
+        if (world == null || world.isEmpty() || world.equals("*")) {
+            world = "global";
         }
-        if (world != null) {
-            world = world.toLowerCase();
-        }
-        return world;
+        return world.toLowerCase();
     }
 }
diff --git a/bukkit/src/main/java/me/lucko/luckperms/bukkit/migration/MigrationPowerfulPerms.java b/bukkit/src/main/java/me/lucko/luckperms/bukkit/migration/MigrationPowerfulPerms.java
index 347e2933b..51834b2eb 100644
--- a/bukkit/src/main/java/me/lucko/luckperms/bukkit/migration/MigrationPowerfulPerms.java
+++ b/bukkit/src/main/java/me/lucko/luckperms/bukkit/migration/MigrationPowerfulPerms.java
@@ -309,7 +309,7 @@ public class MigrationPowerfulPerms extends SubCommand<Object> {
             server = "global";
         }
 
-        NodeBuilder nb = NodeBuilders.determineMostApplicable(node).value(value);
+        NodeBuilder<?, ?> nb = NodeBuilders.determineMostApplicable(node).value(value);
         if (expireAt != 0) nb.expiry(expireAt);
         if (server != null) nb.withContext(DefaultContextKeys.SERVER_KEY, server);
         if (world != null) nb.withContext(DefaultContextKeys.WORLD_KEY, world);
@@ -325,7 +325,7 @@ public class MigrationPowerfulPerms extends SubCommand<Object> {
             expireAt = g.getExpirationDate().getTime() / 1000L;
         }
 
-        NodeBuilder nb = Inheritance.builder(MigrationUtils.standardizeName(group.getName()));
+        NodeBuilder<?, ?> nb = Inheritance.builder(MigrationUtils.standardizeName(group.getName()));
 
         if (expireAt != 0) {
             nb.expiry(expireAt);