diff --git a/deob-ast/src/main/java/dev/openrs2/deob/ast/transform/BitMaskTransformer.java b/deob-ast/src/main/java/dev/openrs2/deob/ast/transform/BitMaskTransformer.java
deleted file mode 100644
index ad4044723e..0000000000
--- a/deob-ast/src/main/java/dev/openrs2/deob/ast/transform/BitMaskTransformer.java
+++ /dev/null
@@ -1,79 +0,0 @@
-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.IntegerLiteralExpr;
-import com.google.common.collect.ImmutableSet;
-import dev.openrs2.deob.ast.util.ExprUtils;
-import dev.openrs2.deob.ast.util.NodeUtils;
-
-public final class BitMaskTransformer extends Transformer {
-	private static final ImmutableSet<BinaryExpr.Operator> SHIFT_OPS = ImmutableSet.of(
-		BinaryExpr.Operator.SIGNED_RIGHT_SHIFT,
-		BinaryExpr.Operator.UNSIGNED_RIGHT_SHIFT
-	);
-
-	private static final ImmutableSet<BinaryExpr.Operator> BITWISE_OPS = ImmutableSet.of(
-		BinaryExpr.Operator.BINARY_AND,
-		BinaryExpr.Operator.BINARY_OR,
-		BinaryExpr.Operator.XOR
-	);
-
-	@Override
-	public void transform(CompilationUnit unit) {
-		NodeUtils.walk(unit, Node.TreeTraversal.POSTORDER, BinaryExpr.class, expr -> {
-			var shiftOp = expr.getOperator();
-			var left = expr.getLeft();
-			var shamtExpr = expr.getRight();
-
-			if (!SHIFT_OPS.contains(shiftOp) || !left.isBinaryExpr() || !shamtExpr.isIntegerLiteralExpr()) {
-				return;
-			}
-
-			var bitwiseExpr = left.asBinaryExpr();
-			var bitwiseOp = bitwiseExpr.getOperator();
-			var argExpr = bitwiseExpr.getLeft();
-			var maskExpr = bitwiseExpr.getRight();
-
-			if (!BITWISE_OPS.contains(bitwiseOp) || !ExprUtils.isIntegerOrLongLiteral(maskExpr)) {
-				return;
-			}
-
-			var shamt = shamtExpr.asIntegerLiteralExpr().asInt();
-			if (maskExpr.isIntegerLiteralExpr()) {
-				var mask = maskExpr.asIntegerLiteralExpr().asInt();
-
-				switch (shiftOp) {
-				case SIGNED_RIGHT_SHIFT:
-					mask >>= shamt;
-					break;
-				case UNSIGNED_RIGHT_SHIFT:
-					mask >>>= shamt;
-					break;
-				default:
-					throw new IllegalStateException();
-				}
-
-				maskExpr = new IntegerLiteralExpr(mask);
-			} else {
-				var mask = maskExpr.asLongLiteralExpr().asLong();
-
-				switch (shiftOp) {
-				case SIGNED_RIGHT_SHIFT:
-					mask >>= shamt;
-					break;
-				case UNSIGNED_RIGHT_SHIFT:
-					mask >>>= shamt;
-					break;
-				default:
-					throw new IllegalStateException();
-				}
-
-				maskExpr = ExprUtils.createLong(mask);
-			}
-
-			expr.replace(new BinaryExpr(new BinaryExpr(argExpr.clone(), shamtExpr.clone(), shiftOp), maskExpr, bitwiseOp));
-		});
-	}
-}
diff --git a/deob-ast/src/main/java/dev/openrs2/deob/ast/transform/BitMaskTransformer.kt b/deob-ast/src/main/java/dev/openrs2/deob/ast/transform/BitMaskTransformer.kt
new file mode 100644
index 0000000000..85173dfa41
--- /dev/null
+++ b/deob-ast/src/main/java/dev/openrs2/deob/ast/transform/BitMaskTransformer.kt
@@ -0,0 +1,68 @@
+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.IntegerLiteralExpr
+import dev.openrs2.deob.ast.util.ExprUtils
+import dev.openrs2.deob.ast.util.NodeUtils
+
+class BitMaskTransformer : Transformer() {
+    override fun transform(unit: CompilationUnit) {
+        NodeUtils.walk(unit, Node.TreeTraversal.POSTORDER, BinaryExpr::class.java) { expr ->
+            val shiftOp = expr.operator
+            val left = expr.left
+            val shamtExpr = expr.right
+
+            if (!SHIFT_OPS.contains(shiftOp) || !left.isBinaryExpr || !shamtExpr.isIntegerLiteralExpr) {
+                return@walk
+            }
+
+            val bitwiseExpr = left.asBinaryExpr()
+            val bitwiseOp = bitwiseExpr.operator
+            val argExpr = bitwiseExpr.left
+            var maskExpr = bitwiseExpr.right
+
+            if (!BITWISE_OPS.contains(bitwiseOp) || !ExprUtils.isIntegerOrLongLiteral(maskExpr)) {
+                return@walk
+            }
+
+            val shamt = shamtExpr.asIntegerLiteralExpr().asInt()
+            if (maskExpr.isIntegerLiteralExpr) {
+                var mask = maskExpr.asIntegerLiteralExpr().asInt()
+
+                mask = when (shiftOp) {
+                    BinaryExpr.Operator.SIGNED_RIGHT_SHIFT -> mask shr shamt
+                    BinaryExpr.Operator.UNSIGNED_RIGHT_SHIFT -> mask ushr shamt
+                    else -> throw IllegalStateException()
+                }
+
+                maskExpr = IntegerLiteralExpr(mask)
+            } else {
+                var mask = maskExpr.asLongLiteralExpr().asLong()
+
+                mask = when (shiftOp) {
+                    BinaryExpr.Operator.SIGNED_RIGHT_SHIFT -> mask shr shamt
+                    BinaryExpr.Operator.UNSIGNED_RIGHT_SHIFT -> mask ushr shamt
+                    else -> throw IllegalStateException()
+                }
+
+                maskExpr = ExprUtils.createLong(mask)
+            }
+
+            expr.replace(BinaryExpr(BinaryExpr(argExpr.clone(), shamtExpr.clone(), shiftOp), maskExpr, bitwiseOp))
+        }
+    }
+
+    companion object {
+        private val SHIFT_OPS = setOf(
+            BinaryExpr.Operator.SIGNED_RIGHT_SHIFT,
+            BinaryExpr.Operator.UNSIGNED_RIGHT_SHIFT
+        )
+        private val BITWISE_OPS = setOf(
+            BinaryExpr.Operator.BINARY_AND,
+            BinaryExpr.Operator.BINARY_OR,
+            BinaryExpr.Operator.XOR
+        )
+    }
+}