diff --git a/deob-ast/src/main/java/dev/openrs2/deob/ast/transform/ComplementTransformer.java b/deob-ast/src/main/java/dev/openrs2/deob/ast/transform/ComplementTransformer.java
deleted file mode 100644
index 424b9d622b..0000000000
--- a/deob-ast/src/main/java/dev/openrs2/deob/ast/transform/ComplementTransformer.java
+++ /dev/null
@@ -1,68 +0,0 @@
-package dev.openrs2.deob.ast.transform;
-
-import java.util.Optional;
-
-import com.github.javaparser.ast.CompilationUnit;
-import com.github.javaparser.ast.Node;
-import com.github.javaparser.ast.expr.BinaryExpr;
-import com.github.javaparser.ast.expr.Expression;
-import com.github.javaparser.ast.expr.IntegerLiteralExpr;
-import com.github.javaparser.ast.expr.UnaryExpr;
-import dev.openrs2.deob.ast.util.ExprUtils;
-import dev.openrs2.deob.ast.util.NodeUtils;
-
-public final class ComplementTransformer extends Transformer {
-	private static boolean isComplement(Expression expr) {
-		return expr.isUnaryExpr() && expr.asUnaryExpr().getOperator() == UnaryExpr.Operator.BITWISE_COMPLEMENT;
-	}
-
-	private static boolean isComplementOrLiteral(Expression expr) {
-		return isComplement(expr) || ExprUtils.isIntegerOrLongLiteral(expr);
-	}
-
-	private static Optional<BinaryExpr.Operator> complement(BinaryExpr.Operator op) {
-		switch (op) {
-		case EQUALS:
-		case NOT_EQUALS:
-			return Optional.of(op);
-		case GREATER:
-			return Optional.of(BinaryExpr.Operator.LESS);
-		case GREATER_EQUALS:
-			return Optional.of(BinaryExpr.Operator.LESS_EQUALS);
-		case LESS:
-			return Optional.of(BinaryExpr.Operator.GREATER);
-		case LESS_EQUALS:
-			return Optional.of(BinaryExpr.Operator.GREATER_EQUALS);
-		default:
-			return Optional.empty();
-		}
-	}
-
-	private static Expression complement(Expression expr) {
-		if (expr.isUnaryExpr()) {
-			return expr.asUnaryExpr().getExpression();
-		} else if (expr.isIntegerLiteralExpr()) {
-			return new IntegerLiteralExpr(~expr.asIntegerLiteralExpr().asInt());
-		} else if (expr.isLongLiteralExpr()) {
-			return ExprUtils.createLong(~expr.asLongLiteralExpr().asLong());
-		} else {
-			throw new IllegalArgumentException();
-		}
-	}
-
-	@Override
-	public void transform(CompilationUnit unit) {
-		NodeUtils.walk(unit, Node.TreeTraversal.POSTORDER, BinaryExpr.class, expr -> {
-			complement(expr.getOperator()).ifPresent(op -> {
-				var left = expr.getLeft();
-				var right = expr.getRight();
-
-				if (isComplementOrLiteral(left) && isComplementOrLiteral(right) && !(ExprUtils.isIntegerOrLongLiteral(left) && ExprUtils.isIntegerOrLongLiteral(right))) {
-					expr.setOperator(op);
-					expr.setLeft(complement(left));
-					expr.setRight(complement(right));
-				}
-			});
-		});
-	}
-}
diff --git a/deob-ast/src/main/java/dev/openrs2/deob/ast/transform/ComplementTransformer.kt b/deob-ast/src/main/java/dev/openrs2/deob/ast/transform/ComplementTransformer.kt
new file mode 100644
index 0000000000..38686c7617
--- /dev/null
+++ b/deob-ast/src/main/java/dev/openrs2/deob/ast/transform/ComplementTransformer.kt
@@ -0,0 +1,58 @@
+package dev.openrs2.deob.ast.transform
+
+import com.github.javaparser.ast.CompilationUnit
+import com.github.javaparser.ast.Node
+import com.github.javaparser.ast.expr.BinaryExpr
+import com.github.javaparser.ast.expr.Expression
+import com.github.javaparser.ast.expr.IntegerLiteralExpr
+import com.github.javaparser.ast.expr.UnaryExpr
+import dev.openrs2.deob.ast.util.ExprUtils
+import dev.openrs2.deob.ast.util.NodeUtils
+
+class ComplementTransformer : Transformer() {
+    override fun transform(unit: CompilationUnit) {
+        NodeUtils.walk(unit, Node.TreeTraversal.POSTORDER, BinaryExpr::class.java) { expr ->
+            val op = complement(expr.operator) ?: return@walk
+
+            val left = expr.left
+            val right = expr.right
+            val bothLiteral = ExprUtils.isIntegerOrLongLiteral(left) && ExprUtils.isIntegerOrLongLiteral(right)
+
+            if (isComplementOrLiteral(left) && isComplementOrLiteral(right) && !bothLiteral) {
+                expr.operator = op
+                expr.left = complement(left)
+                expr.right = complement(right)
+            }
+        }
+    }
+
+    companion object {
+        private fun isComplement(expr: Expression): Boolean {
+            return expr.isUnaryExpr && expr.asUnaryExpr().operator == UnaryExpr.Operator.BITWISE_COMPLEMENT
+        }
+
+        private fun isComplementOrLiteral(expr: Expression): Boolean {
+            return isComplement(expr) || ExprUtils.isIntegerOrLongLiteral(expr)
+        }
+
+        private fun complement(op: BinaryExpr.Operator): BinaryExpr.Operator? {
+            return when (op) {
+                BinaryExpr.Operator.EQUALS, BinaryExpr.Operator.NOT_EQUALS -> op
+                BinaryExpr.Operator.GREATER -> BinaryExpr.Operator.LESS
+                BinaryExpr.Operator.GREATER_EQUALS -> BinaryExpr.Operator.LESS_EQUALS
+                BinaryExpr.Operator.LESS -> BinaryExpr.Operator.GREATER
+                BinaryExpr.Operator.LESS_EQUALS -> BinaryExpr.Operator.GREATER_EQUALS
+                else -> null
+            }
+        }
+
+        private fun complement(expr: Expression): Expression {
+            return when {
+                expr.isUnaryExpr -> expr.asUnaryExpr().expression
+                expr.isIntegerLiteralExpr -> IntegerLiteralExpr(expr.asIntegerLiteralExpr().asInt().inv())
+                expr.isLongLiteralExpr -> ExprUtils.createLong(expr.asLongLiteralExpr().asLong().inv())
+                else -> throw IllegalArgumentException()
+            }
+        }
+    }
+}