diff --git a/src/calltree.js b/src/calltree.js
index 57ebae0..6649973 100644
--- a/src/calltree.js
+++ b/src/calltree.js
@@ -750,7 +750,7 @@ const select_return_value = state => {
 
   } else {
     result_node = find_node(frame, n => 
-      n.type == 'function_call'
+      (n.type == 'function_call' || n.type == 'new')
       && n.result != null
       && n.result.call.id == state.current_calltree_node.id
     )
@@ -790,7 +790,7 @@ const select_arguments = (state, with_focus = true) => {
 
   } else {
     const call = find_node(frame, n => 
-      n.type == 'function_call'
+      (n.type == 'function_call' || n.type == 'new')
       && n.result != null
       && n.result.call.id == state.current_calltree_node.id
     )
diff --git a/src/editor/calltree.js b/src/editor/calltree.js
index d90b17e..abc4ad2 100644
--- a/src/editor/calltree.js
+++ b/src/editor/calltree.js
@@ -112,8 +112,8 @@ export class CallTree {
                 + (n.fn.__location == null ? ' native' : '')
             ,
             // TODO show `this` argument
-            n.fn.name
-            ,
+            (n.is_new ? 'new ' : ''),
+            n.fn.name,
             '(' ,
              ...join(
                n.args.map(
diff --git a/src/eval.js b/src/eval.js
index c058ab9..1028ac9 100644
--- a/src/eval.js
+++ b/src/eval.js
@@ -222,7 +222,8 @@ const codegen = (node, cxt, parent) => {
   } else if(node.type == 'spread'){
     return '...(' + do_codegen(node.expr) + ')'
   } else if(node.type == 'new') {
-    return '(new (' + codegen(node.constructor) + ')(' + node.args.map(do_codegen).join(',') + '))'
+    const args = `[${node.args.children.map(do_codegen).join(',')}]`
+    return `trace_call(${do_codegen(node.constructor)}, null, ${args}, true)`
   } else if(node.type == 'grouping'){
     return '(' + do_codegen(node.expr) + ')'
   } else if(node.type == 'array_destructuring') {
@@ -441,13 +442,20 @@ export const eval_modules = (
       return result
     }
 
-    const trace_call = (fn, context, args) => {
-      if(fn != null && fn.__location != null) {
+    const trace_call = (fn, context, args, is_new = false) => {
+      if(fn != null && fn.__location != null && !is_new) {
+        // Call will be traced, because tracing code is already embedded inside
+        // fn
         return fn(...args)
       }
 
       if(typeof(fn) != 'function') {
-        return fn.apply(context, args)
+        // Raise error
+        if(is_new) {
+          return new fn(...args)
+        } else {
+          return fn.apply(context, args)
+        }
       }
 
       const children_copy = children
@@ -465,7 +473,11 @@ export const eval_modules = (
 
       try {
         if(!is_log) {
-          value = fn.apply(context, args)
+          if(is_new) {
+            value = new fn(...args)
+          } else {
+            value = fn.apply(context, args)
+          }
         } else {
           value = undefined
         }
@@ -489,6 +501,7 @@ export const eval_modules = (
           args,
           context,
           is_log,
+          is_new,
         }
 
         const should_record_call = stack.pop()
@@ -799,7 +812,7 @@ const do_eval_frame_expr = (node, scope, callsleft) => {
       {}
     )
     return {ok, children, value, calls}
-  } else if(node.type == 'function_call'){
+  } else if(node.type == 'function_call' || node.type == 'new'){
     const {ok, children, calls} = eval_children(node, scope, callsleft)
     if(!ok) {
       return {ok: false, children, calls}
@@ -940,15 +953,6 @@ const do_eval_frame_expr = (node, scope, callsleft) => {
       return eval_binary_expr(node, scope, callsleft)
     }
 
-  } else if(node.type == 'new') {
-    const {ok, children, calls} = eval_children(node, scope, callsleft)
-    if(!ok) {
-      return {ok, children, calls}
-    } else {
-      const [constructor, ...args] = children
-      const value = new (constructor.result.value)(...args.map(a => a.result.value))
-      return {ok, children, value, calls}
-    }
   } else if(node.type == 'grouping'){
     const {ok, children, calls} = eval_children(node, scope, callsleft)
     if(!ok) {
diff --git a/src/parse_js.js b/src/parse_js.js
index b5ebe1f..4bc78c3 100644
--- a/src/parse_js.js
+++ b/src/parse_js.js
@@ -984,11 +984,20 @@ const new_expr = if_ok(
       array_element,
     )
   ]),
-  ({value, ...node}) => ({
-    ...node,
-    type: 'new',
-    children: [value[1], ...value[2].value],
-  })
+  ({value, ...node}) => {
+    const {value: args, ..._call_args} = value[2]
+    const call_args = {
+      ..._call_args,
+      children: args,
+      not_evaluatable: args.length == 0,
+      type: 'call_args',
+    }
+    return {
+      ...node,
+      type: 'new',
+      children: [value[1], call_args],
+    }
+  }
 )
 
 const primary = if_fail(
@@ -1384,7 +1393,7 @@ const update_children_not_rec = (node, children = node.children) => {
       expr: children[0]
     }
   } else if(node.type == 'new') {
-    return {...node, constructor: children[0], args: children.slice(1)}
+    return {...node, constructor: children[0], args: children[1]}
   } else if(node.type == 'grouping') {
     return {...node, expr: children[0]}
   } else if(node.type == 'return') {
diff --git a/test/test.js b/test/test.js
index 84d0d3f..d873518 100644
--- a/test/test.js
+++ b/test/test.js
@@ -423,6 +423,35 @@ export const tests = [
     `, 'test')
   }),
 
+  test('new calls are recorded in calltree', () => {
+    const code = `
+      const make_class = new Function("return class { constructor(x) { x() } }")
+      const clazz = make_class()
+      const x = () => 1
+      new clazz(x)
+    `
+    const i = test_initial_state(code)
+    const find_call = COMMANDS.move_cursor(i, code.indexOf('1')).state
+    assert_equal(root_calltree_node(find_call).children.length, 3)
+    const x_call = root_calltree_node(find_call).children[2].children[0]
+    assert_equal(x_call.fn.name, 'x')
+  }),
+
+  test('new calls step into', () => {
+    const code = `new Set()`
+    const i = test_initial_state(code)
+    const into = COMMANDS.calltree.arrow_down(i)
+    assert_equal(into.state.current_calltree_node.fn.name, 'Set')
+    assert_equal(into.state.current_calltree_node.is_new, true)
+  }),
+
+  test('new call non-constructor', () => {
+    assert_code_error(
+      `const x = () => 1; new x()`,
+      'TypeError: fn is not a constructor'
+    )
+  }),
+
   test('method chaining', () => {
     assert_code_evals_to(
       `
@@ -1676,7 +1705,7 @@ const y = x()`
       const y = () => 1
       const deep_error = x => {
         if(x == 10) {
-          throw new Error('deep_error')
+          throw 'deep_error'
         } else {
           y()
           deep_error(x + 1)
@@ -1701,7 +1730,7 @@ const y = x()`
 
     assert_equal(depth(first), 10)
     assert_equal(first.ok, false)
-    assert_equal(first.error.message, 'deep_error')
+    assert_equal(first.error, 'deep_error')
   }),
 
   /* Test when node where error occured has subcalls */
@@ -1958,6 +1987,14 @@ const y = x()`
     const {state: s3, effects} = COMMANDS.calltree.select_return_value(s2)
     assert_equal(s3.selection_state.result.value, [1, 1, 1])
   }),
+
+  test('select_return_value new call', () => {
+    const code = `new String('1')`
+    const s1 = test_initial_state(code)
+    const s2 = COMMANDS.calltree.arrow_right(s1).state
+    const {state: s3, effects} = COMMANDS.calltree.select_return_value(s2)
+    assert_equal(s3.selection_state.result.value, '1')
+  }),
   
   test('select_arguments not_expanded', () => {
     const code = `
@@ -1989,6 +2026,14 @@ const y = x()`
     assert_equal(s3.effects, {type: 'set_focus'})
   }),
 
+  test('select_arguments new call', () => {
+    const code = `new String("1")`
+    const s1 = test_initial_state(code)
+    const s2 = COMMANDS.calltree.arrow_right(s1).state
+    const s3 = COMMANDS.calltree.select_arguments(s2).state
+    assert_equal(s3.selection_state.result, {ok: true, value: ["1"]})
+  }),
+
   test('move_cursor arguments', () => {
     const code = `
       const x = (a, b) => { }