diff --git a/deob-ast/src/main/java/dev/openrs2/deob/ast/transform/IfElseTransformer.java b/deob-ast/src/main/java/dev/openrs2/deob/ast/transform/IfElseTransformer.java
deleted file mode 100644
index 58b999db..00000000
--- a/deob-ast/src/main/java/dev/openrs2/deob/ast/transform/IfElseTransformer.java
+++ /dev/null
@@ -1,158 +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.stmt.BlockStmt;
-import com.github.javaparser.ast.stmt.IfStmt;
-import com.github.javaparser.ast.stmt.Statement;
-import dev.openrs2.deob.ast.util.ExprUtils;
-import dev.openrs2.deob.ast.util.NodeUtils;
-
-public final class IfElseTransformer extends Transformer {
-	private static boolean isIf(Statement stmt) {
-		if (stmt.isIfStmt()) {
-			return true;
-		} else if (stmt.isBlockStmt()) {
-			var stmts = stmt.asBlockStmt().getStatements();
-			return stmts.size() == 1 && stmts.get(0).isIfStmt();
-		} else {
-			return false;
-		}
-	}
-
-	private static Statement getIf(Statement stmt) {
-		if (stmt.isIfStmt()) {
-			return stmt.clone();
-		} else if (stmt.isBlockStmt()) {
-			var stmts = stmt.asBlockStmt().getStatements();
-			if (stmts.size() == 1) {
-				Statement head = stmts.get(0);
-				if (head.isIfStmt()) {
-					return head.clone();
-				}
-			}
-		}
-
-		throw new IllegalArgumentException();
-	}
-
-	private static boolean isTailThrowOrReturn(Statement stmt) {
-		if (stmt.isThrowStmt() || stmt.isReturnStmt()) {
-			return true;
-		} else if (stmt.isBlockStmt()) {
-			var stmts = stmt.asBlockStmt().getStatements();
-			if (stmts.isEmpty()) {
-				return false;
-			}
-
-			var tail = stmts.get(stmts.size() - 1);
-			return tail.isThrowStmt() || tail.isReturnStmt();
-		} else {
-			return false;
-		}
-	}
-
-	@Override
-	public void transform(CompilationUnit unit) {
-		NodeUtils.walk(unit, Node.TreeTraversal.POSTORDER, IfStmt.class, stmt -> {
-			stmt.getElseStmt().ifPresent(elseStmt -> {
-				var condition = stmt.getCondition();
-				var thenStmt = stmt.getThenStmt();
-				if (isIf(thenStmt) && !isIf(elseStmt)) {
-					stmt.setCondition(ExprUtils.not(condition));
-					stmt.setThenStmt(elseStmt.clone());
-					stmt.setElseStmt(thenStmt.clone());
-				} else if (!isIf(thenStmt) && isIf(elseStmt)) {
-					/*
-					 * Don't consider any more conditions for swapping the
-					 * if/else branches, as it'll introduce another level of
-					 * indentation.
-					 */
-					return;
-				}
-
-				/* Prefer fewer NOTs in the if condition. */
-				var notCondition = ExprUtils.not(condition);
-				if (ExprUtils.countNots(notCondition) < ExprUtils.countNots(condition)) {
-					stmt.setCondition(notCondition);
-					if (elseStmt.isIfStmt()) {
-						var block = new BlockStmt();
-						block.getStatements().add(elseStmt.clone());
-						stmt.setThenStmt(block);
-					} else {
-						stmt.setThenStmt(elseStmt.clone());
-					}
-					stmt.setElseStmt(thenStmt.clone());
-				}
-			});
-		});
-
-		NodeUtils.walk(unit, Node.TreeTraversal.POSTORDER, IfStmt.class, stmt -> {
-			stmt.getElseStmt().ifPresent(elseStmt -> {
-				if (isIf(elseStmt)) {
-					stmt.setElseStmt(getIf(elseStmt));
-				}
-			});
-		});
-
-		/*
-		 * Rewrite:
-		 *
-		 * ...
-		 * } else {
-		 *     if (x != 123) {
-		 *         ...
-		 *         throw ...;
-		 *     }
-		 *     ...
-		 * }
-		 *
-		 * to:
-		 *
-		 * ...
-		 * } else if (x == 123) {
-		 *     ...
-		 * } else {
-		 *     ...
-		 *     throw ...;
-		 * }
-		 */
-		NodeUtils.walk(unit, Node.TreeTraversal.POSTORDER, IfStmt.class, stmt -> {
-			stmt.getElseStmt().ifPresent(elseStmt -> {
-				/* match */
-				if (!elseStmt.isBlockStmt()) {
-					return;
-				}
-
-				var blockStmt = elseStmt.asBlockStmt();
-				var statements = blockStmt.getStatements();
-				if (statements.isEmpty()) {
-					return;
-				}
-
-				var head = statements.get(0);
-				if (!head.isIfStmt()) {
-					return;
-				}
-
-				var ifStmt = head.asIfStmt();
-				if (ifStmt.getElseStmt().isPresent()) {
-					return;
-				}
-
-				var thenStmt = ifStmt.getThenStmt();
-				if (!isTailThrowOrReturn(thenStmt)) {
-					return;
-				}
-
-				/* rewrite */
-				var condition = ExprUtils.not(ifStmt.getCondition());
-
-				var tail = blockStmt.clone();
-				tail.getStatements().remove(0);
-
-				elseStmt.replace(new IfStmt(condition, tail, thenStmt.clone()));
-			});
-		});
-	}
-}
diff --git a/deob-ast/src/main/java/dev/openrs2/deob/ast/transform/IfElseTransformer.kt b/deob-ast/src/main/java/dev/openrs2/deob/ast/transform/IfElseTransformer.kt
new file mode 100644
index 00000000..359b541b
--- /dev/null
+++ b/deob-ast/src/main/java/dev/openrs2/deob/ast/transform/IfElseTransformer.kt
@@ -0,0 +1,158 @@
+package dev.openrs2.deob.ast.transform
+
+import com.github.javaparser.ast.CompilationUnit
+import com.github.javaparser.ast.Node
+import com.github.javaparser.ast.stmt.BlockStmt
+import com.github.javaparser.ast.stmt.IfStmt
+import com.github.javaparser.ast.stmt.Statement
+import dev.openrs2.deob.ast.util.ExprUtils
+import dev.openrs2.deob.ast.util.NodeUtils
+
+class IfElseTransformer : Transformer() {
+    override fun transform(unit: CompilationUnit) {
+        NodeUtils.walk(unit, Node.TreeTraversal.POSTORDER, IfStmt::class.java) { stmt ->
+            stmt.elseStmt.ifPresent { elseStmt: Statement ->
+                val condition = stmt.condition
+                val thenStmt = stmt.thenStmt
+                if (isIf(thenStmt) && !isIf(elseStmt)) {
+                    stmt.condition = ExprUtils.not(condition)
+                    stmt.thenStmt = elseStmt.clone()
+                    stmt.setElseStmt(thenStmt.clone())
+                } else if (!isIf(thenStmt) && isIf(elseStmt)) {
+                    /*
+                     * Don't consider any more conditions for swapping the
+                     * if/else branches, as it'll introduce another level of
+                     * indentation.
+                     */
+                    return@ifPresent
+                }
+
+                // Prefer fewer NOTs in the if condition
+                val notCondition = ExprUtils.not(condition)
+                if (ExprUtils.countNots(notCondition) < ExprUtils.countNots(condition)) {
+                    stmt.condition = notCondition
+                    if (elseStmt.isIfStmt) {
+                        val block = BlockStmt()
+                        block.statements.add(elseStmt.clone())
+                        stmt.thenStmt = block
+                    } else {
+                        stmt.thenStmt = elseStmt.clone()
+                    }
+                    stmt.setElseStmt(thenStmt.clone())
+                }
+            }
+        }
+
+        NodeUtils.walk(unit, Node.TreeTraversal.POSTORDER, IfStmt::class.java) { stmt ->
+            stmt.elseStmt.ifPresent { elseStmt ->
+                if (isIf(elseStmt)) {
+                    stmt.setElseStmt(getIf(elseStmt))
+                }
+            }
+        }
+
+        /*
+         * Rewrite:
+         *
+         * ...
+         * } else {
+         *     if (x != 123) {
+         *         ...
+         *         throw ...;
+         *     }
+         *     ...
+         * }
+         *
+         * to:
+         *
+         * ...
+         * } else if (x == 123) {
+         *     ...
+         * } else {
+         *     ...
+         *     throw ...;
+         * }
+         */
+        NodeUtils.walk(unit, Node.TreeTraversal.POSTORDER, IfStmt::class.java) { stmt ->
+            stmt.elseStmt.ifPresent { elseStmt ->
+                // match
+                if (!elseStmt.isBlockStmt) {
+                    return@ifPresent
+                }
+
+                val blockStmt = elseStmt.asBlockStmt()
+                val statements = blockStmt.statements
+                if (statements.isEmpty()) {
+                    return@ifPresent
+                }
+
+                val head = statements[0]
+                if (!head.isIfStmt) {
+                    return@ifPresent
+                }
+
+                val ifStmt = head.asIfStmt()
+                if (ifStmt.elseStmt.isPresent) {
+                    return@ifPresent
+                }
+
+                val thenStmt = ifStmt.thenStmt
+                if (!isTailThrowOrReturn(thenStmt)) {
+                    return@ifPresent
+                }
+
+                // rewrite
+                val condition = ExprUtils.not(ifStmt.condition)
+
+                val tail = blockStmt.clone()
+                tail.statements.removeAt(0)
+
+                elseStmt.replace(IfStmt(condition, tail, thenStmt.clone()))
+            }
+        }
+    }
+
+    companion object {
+        private fun isIf(stmt: Statement): Boolean {
+            return if (stmt.isIfStmt) {
+                true
+            } else if (stmt.isBlockStmt) {
+                val stmts = stmt.asBlockStmt().statements
+                stmts.size == 1 && stmts[0].isIfStmt
+            } else {
+                false
+            }
+        }
+
+        private fun getIf(stmt: Statement): Statement {
+            if (stmt.isIfStmt) {
+                return stmt.clone()
+            } else if (stmt.isBlockStmt) {
+                val stmts = stmt.asBlockStmt().statements
+                if (stmts.size == 1) {
+                    val head = stmts[0]
+                    if (head.isIfStmt) {
+                        return head.clone()
+                    }
+                }
+            }
+            throw IllegalArgumentException()
+        }
+
+        private fun isTailThrowOrReturn(stmt: Statement): Boolean {
+            return if (stmt.isThrowStmt || stmt.isReturnStmt) {
+                true
+            } else if (stmt.isBlockStmt) {
+                val stmts = stmt.asBlockStmt().statements
+                if (stmts.isEmpty()) {
+                    return false
+                }
+
+                val tail = stmts[stmts.size - 1]
+                tail.isThrowStmt || tail.isReturnStmt
+            } else {
+                false
+            }
+        }
+    }
+}