diff --git a/gradle.properties b/gradle.properties
index b0d3267f..455b5e3c 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -5,7 +5,7 @@ org.gradle.jvmargs=-Xmx1G
 	# check these on https://fabricmc.net/use
     # or better: https://modmuss50.me/fabric.html
 	minecraft_version=1.16.4
-	yarn_mappings=1.16.4+build.1
+	yarn_mappings=1.16.4+build.6
 	loader_version=0.10.6+build.214
 
 # Mod Properties
diff --git a/src/main/java/carpet/mixins/World_movableTEMixin.java b/src/main/java/carpet/mixins/World_movableTEMixin.java
index a1a48117..160306e5 100644
--- a/src/main/java/carpet/mixins/World_movableTEMixin.java
+++ b/src/main/java/carpet/mixins/World_movableTEMixin.java
@@ -63,7 +63,7 @@ public abstract class World_movableTEMixin implements WorldInterface, WorldAcces
         if ((Object) this instanceof EmptyChunk)
             return false;
         
-        if (World.isHeightInvalid(blockPos_1))
+        if (World.isOutOfBuildLimitVertically(blockPos_1))
         {
             return false;
         }
diff --git a/src/main/java/carpet/script/api/Auxiliary.java b/src/main/java/carpet/script/api/Auxiliary.java
index d05251f6..2a38bfd1 100644
--- a/src/main/java/carpet/script/api/Auxiliary.java
+++ b/src/main/java/carpet/script/api/Auxiliary.java
@@ -614,7 +614,7 @@ public class Auxiliary {
             return (cc, tt) -> retval;
         });
 
-        expression.addLazyFunction("plop", 4, (c, t, lv) ->{
+        expression.addLazyFunction("plop", -1, (c, t, lv) ->{
             BlockArgument locator = BlockArgument.findIn((CarpetContext)c, lv, 0);
             if (lv.size() <= locator.offset)
                 throw new InternalExpressionException("'plop' needs extra argument indicating what to plop");
@@ -624,7 +624,6 @@ public class Auxiliary {
             {
                 Boolean res = FeatureGenerator.plop(what, ((CarpetContext) c).s.getWorld(), locator.block.getPos());
 
-                //Boolean res = FeatureGenerator.spawn(what, ((CarpetContext) c).s.getWorld(), locator.block.getPos());
                 if (res == null)
                     return;
                 if (what.equalsIgnoreCase("boulder"))  // there might be more of those