diff --git a/src/qweb/compilation_context.ts b/src/qweb/compilation_context.ts
index c2656771..35dde215 100644
--- a/src/qweb/compilation_context.ts
+++ b/src/qweb/compilation_context.ts
@@ -196,11 +196,12 @@ export class CompilationContext {
     const protectID = this.generateID();
     this.rootContext.protectedScopeNumber++;
     this.rootContext.shouldDefineScope = true;
-    const scopeExpr = codeBlock
-      ? `Object.create(scope);`
-      : `Object.assign(Object.create(context), scope);`;
+    const scopeExpr = `Object.create(scope);`;
     this.addLine(`let _origScope${protectID} = scope;`);
     this.addLine(`scope = ${scopeExpr}`);
+    if (!codeBlock) {
+      this.addLine(`scope.__access_mode__ = 'ro';`);
+    }
     return protectID;
   }
   stopProtectScope(protectID: number) {
diff --git a/src/qweb/qweb.ts b/src/qweb/qweb.ts
index bf48c88a..662a841c 100644
--- a/src/qweb/qweb.ts
+++ b/src/qweb/qweb.ts
@@ -133,7 +133,7 @@ const UTILS: Utils = {
   },
   getScope(obj, property: string) {
     const obj0 = obj;
-    while (obj && !obj.hasOwnProperty(property)) {
+    while (obj && !obj.hasOwnProperty(property) && !(obj.hasOwnProperty('__access_mode__') && obj.__access_mode__ === 'ro')) {
       const newObj = obj.__proto__;
       if (!newObj || isComponent(newObj)) {
         return obj0;
diff --git a/tests/component/__snapshots__/component.test.ts.snap b/tests/component/__snapshots__/component.test.ts.snap
index 5e7fc722..6ea5f6d3 100644
--- a/tests/component/__snapshots__/component.test.ts.snap
+++ b/tests/component/__snapshots__/component.test.ts.snap
@@ -1282,7 +1282,8 @@ exports[`other directives with t-component t-set can't alter in t-call body 1`]
     }
     {
         let _origScope4 = scope;
-        scope = Object.assign(Object.create(context), scope);
+        scope = Object.create(scope);
+        scope.__access_mode__ = 'ro';
         {
             let c__0 = [];
             utils.getScope(scope, 'iter').iter = 'inCall';
diff --git a/tests/qweb/__snapshots__/qweb.test.ts.snap b/tests/qweb/__snapshots__/qweb.test.ts.snap
index 5f587349..3a0d8d16 100644
--- a/tests/qweb/__snapshots__/qweb.test.ts.snap
+++ b/tests/qweb/__snapshots__/qweb.test.ts.snap
@@ -774,12 +774,14 @@ exports[`misc global 1`] = `
         }
         {
             let _origScope10 = scope;
-            scope = Object.assign(Object.create(context), scope);
+            scope = Object.create(scope);
+            scope.__access_mode__ = 'ro';
             {
                 let c__0 = [];
                 {
                     let _origScope13 = scope;
-                    scope = Object.assign(Object.create(context), scope);
+                    scope = Object.create(scope);
+                    scope.__access_mode__ = 'ro';
                     {
                         let c__0 = [];
                         utils.getScope(scope, 'foo').foo = 'aaa';
@@ -1150,7 +1152,8 @@ exports[`t-call (template calling call with several sub nodes on same line 1`] =
     let vn1 = h('div', p1, c1);
     {
         let _origScope3 = scope;
-        scope = Object.assign(Object.create(context), scope);
+        scope = Object.create(scope);
+        scope.__access_mode__ = 'ro';
         {
             let c__0 = [];
             let c4 = [], p4 = {key:4};
@@ -1198,7 +1201,8 @@ exports[`t-call (template calling cascading t-call t-raw='0' 1`] = `
     let vn1 = h('div', p1, c1);
     {
         let _origScope12 = scope;
-        scope = Object.assign(Object.create(context), scope);
+        scope = Object.create(scope);
+        scope.__access_mode__ = 'ro';
         {
             let c__0 = [];
             let c13 = [], p13 = {key:13};
@@ -1288,7 +1292,8 @@ exports[`t-call (template calling recursive template, part 2 1`] = `
     let vn1 = h('div', p1, c1);
     {
         let _origScope11 = scope;
-        scope = Object.assign(Object.create(context), scope);
+        scope = Object.create(scope);
+        scope.__access_mode__ = 'ro';
         {
             let c__0 = [];
             utils.getScope(scope, 'node').node = scope['root'];
@@ -1339,7 +1344,8 @@ exports[`t-call (template calling recursive template, part 2 2`] = `
         let key1 = i1;
         {
             let _origScope9 = scope;
-            scope = Object.assign(Object.create(context), scope);
+            scope = Object.create(scope);
+            scope.__access_mode__ = 'ro';
             {
                 let c__0 = [];
                 utils.getScope(scope, 'node').node = scope['subtree'];
@@ -1365,7 +1371,8 @@ exports[`t-call (template calling recursive template, part 3 1`] = `
     let vn1 = h('div', p1, c1);
     {
         let _origScope11 = scope;
-        scope = Object.assign(Object.create(context), scope);
+        scope = Object.create(scope);
+        scope.__access_mode__ = 'ro';
         {
             let c__0 = [];
             utils.getScope(scope, 'node').node = scope['root'];
@@ -1416,7 +1423,93 @@ exports[`t-call (template calling recursive template, part 3 2`] = `
         let key1 = i1;
         {
             let _origScope9 = scope;
-            scope = Object.assign(Object.create(context), scope);
+            scope = Object.create(scope);
+            scope.__access_mode__ = 'ro';
+            {
+                let c__0 = [];
+                utils.getScope(scope, 'node').node = scope['subtree'];
+                scope[utils.zero] = c__0;
+            }
+            let k10 = \`__10__\${key0}__\${key1}__\`;
+            this.subTemplates['nodeTemplate'].call(this, scope, Object.assign({}, extra, {parentNode: c2, parent: utils.getComponent(context), key: k10}));
+            scope = _origScope9;
+        }
+    }
+    scope = _origScope8;
+}"
+`;
+
+exports[`t-call (template calling recursive template, part 4: with t-set recursive index 1`] = `
+"function anonymous(context, extra
+) {
+    // Template name: \\"Parent\\"
+    let utils = this.constructor.utils;
+    let scope = Object.create(context);
+    let h = this.h;
+    let c1 = [], p1 = {key:1};
+    let vn1 = h('div', p1, c1);
+    {
+        let _origScope11 = scope;
+        scope = Object.create(scope);
+        scope.__access_mode__ = 'ro';
+        {
+            let c__0 = [];
+            utils.getScope(scope, 'recursive_idx').recursive_idx = 1;
+            utils.getScope(scope, 'node').node = scope['root'];
+            scope[utils.zero] = c__0;
+        }
+        this.subTemplates['nodeTemplate'].call(this, scope, Object.assign({}, extra, {parentNode: c1, parent: utils.getComponent(context), key: '__12__'}));
+        scope = _origScope11;
+    }
+    return vn1;
+}"
+`;
+
+exports[`t-call (template calling recursive template, part 4: with t-set recursive index 2`] = `
+"function anonymous(context, extra
+) {
+    // Template name: \\"nodeTemplate\\"
+    let utils = this.constructor.utils;
+    let scope = Object.create(context);
+    let h = this.h;
+    let c1 = extra.parentNode;
+    let key0 = extra.key || \\"\\";
+    let c2 = [], p2 = {key:\`\${key0}_2\`};
+    let vn2 = h('div', p2, c2);
+    c1.push(vn2);
+    scope.recursive_idx = scope.recursive_idx+1;
+    let c3 = [], p3 = {key:\`\${key0}_3\`};
+    let vn3 = h('p', p3, c3);
+    c2.push(vn3);
+    let _4 = scope['node'].val;
+    if (_4 != null) {
+        c3.push({text: _4});
+    }
+    c3.push({text: \` \`});
+    if (scope.recursive_idx != null) {
+        c3.push({text: scope.recursive_idx});
+    }
+    let _5 = scope['node'].children||[];
+    if (!_5) { throw new Error('QWeb error: Invalid loop expression')}
+    let _6 = _7 = _5;
+    if (!(_5 instanceof Array)) {
+        _6 = Object.keys(_5);
+        _7 = Object.values(_5);
+    }
+    let _length6 = _6.length;
+    let _origScope8 = scope;
+    scope = Object.create(scope);
+    for (let i1 = 0; i1 < _length6; i1++) {
+        scope.subtree_first = i1 === 0
+        scope.subtree_last = i1 === _length6 - 1
+        scope.subtree_index = i1
+        scope.subtree = _6[i1]
+        scope.subtree_value = _7[i1]
+        let key1 = i1;
+        {
+            let _origScope9 = scope;
+            scope = Object.create(scope);
+            scope.__access_mode__ = 'ro';
             {
                 let c__0 = [];
                 utils.getScope(scope, 'node').node = scope['subtree'];
@@ -1442,7 +1535,8 @@ exports[`t-call (template calling scoped parameters 1`] = `
     let vn1 = h('div', p1, c1);
     {
         let _origScope2 = scope;
-        scope = Object.assign(Object.create(context), scope);
+        scope = Object.create(scope);
+        scope.__access_mode__ = 'ro';
         {
             let c__0 = [];
             utils.getScope(scope, 'foo').foo = 42;
@@ -1517,7 +1611,8 @@ exports[`t-call (template calling t-call with t-set inside and outside 1`] = `
         utils.getScope(scope, 'val').val = scope['v'].val;
         {
             let _origScope8 = scope;
-            scope = Object.assign(Object.create(context), scope);
+            scope = Object.create(scope);
+            scope.__access_mode__ = 'ro';
             {
                 let c__0 = [];
                 utils.getScope(scope, 'val3').val3 = scope.val*3;
@@ -1564,7 +1659,8 @@ exports[`t-call (template calling t-call, conditional and t-set in t-call body 1
     else if (scope.v1==='elif') {
         {
             let _origScope6 = scope;
-            scope = Object.assign(Object.create(context), scope);
+            scope = Object.create(scope);
+            scope.__access_mode__ = 'ro';
             {
                 let c__0 = [];
                 utils.getScope(scope, 'v').v = 'success';
@@ -1602,7 +1698,8 @@ exports[`t-call (template calling with unused body 1`] = `
     let h = this.h;
     {
         let _origScope3 = scope;
-        scope = Object.assign(Object.create(context), scope);
+        scope = Object.create(scope);
+        scope.__access_mode__ = 'ro';
         {
             let c__0 = [];
             c__0.push({text: \`WHEEE\`});
@@ -1627,7 +1724,8 @@ exports[`t-call (template calling with unused setbody 1`] = `
     let h = this.h;
     {
         let _origScope3 = scope;
-        scope = Object.assign(Object.create(context), scope);
+        scope = Object.create(scope);
+        scope.__access_mode__ = 'ro';
         {
             let c__0 = [];
             utils.getScope(scope, 'qux').qux = 3;
@@ -1652,7 +1750,8 @@ exports[`t-call (template calling with used body 1`] = `
     let h = this.h;
     {
         let _origScope3 = scope;
-        scope = Object.assign(Object.create(context), scope);
+        scope = Object.create(scope);
+        scope.__access_mode__ = 'ro';
         {
             let c__0 = [];
             c__0.push({text: \`ok\`});
@@ -1678,7 +1777,8 @@ exports[`t-call (template calling with used set body 1`] = `
     let vn1 = h('span', p1, c1);
     {
         let _origScope3 = scope;
-        scope = Object.assign(Object.create(context), scope);
+        scope = Object.create(scope);
+        scope.__access_mode__ = 'ro';
         {
             let c__0 = [];
             utils.getScope(scope, 'foo').foo = 'ok';
@@ -1839,7 +1939,8 @@ exports[`t-esc t-esc is escaped 1`] = `
     scope.var = c2
     if (scope.var != null) {
         let _origScope4 = scope;
-        scope = Object.assign(Object.create(context), scope);
+        scope = Object.create(scope);
+        scope.__access_mode__ = 'ro';
         scope.var = scope.var instanceof utils.VDomArray ? utils.vDomToString(scope.var) : scope.var;
         c1.push({text: scope.var});
         scope = _origScope4;
@@ -1875,7 +1976,8 @@ exports[`t-esc t-esc=0 is escaped 1`] = `
     let vn1 = h('div', p1, c1);
     {
         let _origScope3 = scope;
-        scope = Object.assign(Object.create(context), scope);
+        scope = Object.create(scope);
+        scope.__access_mode__ = 'ro';
         {
             let c__0 = [];
             let c4 = [], p4 = {key:4};
@@ -2948,7 +3050,8 @@ exports[`t-set set from body literal 1`] = `
     scope.value = c1
     if (scope.value != null) {
         let _origScope2 = scope;
-        scope = Object.assign(Object.create(context), scope);
+        scope = Object.create(scope);
+        scope.__access_mode__ = 'ro';
         scope.value = scope.value instanceof utils.VDomArray ? utils.vDomToString(scope.value) : scope.value;
         let vn3 = {text: scope.value};
         result = vn3
@@ -2975,7 +3078,8 @@ exports[`t-set set from body lookup 1`] = `
     scope.stuff = c2
     if (scope.stuff != null) {
         let _origScope4 = scope;
-        scope = Object.assign(Object.create(context), scope);
+        scope = Object.create(scope);
+        scope.__access_mode__ = 'ro';
         scope.stuff = scope.stuff instanceof utils.VDomArray ? utils.vDomToString(scope.stuff) : scope.stuff;
         c1.push({text: scope.stuff});
         scope = _origScope4;
@@ -3123,7 +3227,8 @@ exports[`t-set t-set with content and sub t-esc 1`] = `
     scope.setvar = c2
     if (scope.setvar != null) {
         let _origScope4 = scope;
-        scope = Object.assign(Object.create(context), scope);
+        scope = Object.create(scope);
+        scope.__access_mode__ = 'ro';
         scope.setvar = scope.setvar instanceof utils.VDomArray ? utils.vDomToString(scope.setvar) : scope.setvar;
         c1.push({text: scope.setvar});
         scope = _origScope4;
@@ -3215,7 +3320,8 @@ exports[`t-set t-set, t-if, and mix of expression/body lookup, 1 1`] = `
     }
     if (scope.ourvar != null) {
         let _origScope3 = scope;
-        scope = Object.assign(Object.create(context), scope);
+        scope = Object.create(scope);
+        scope.__access_mode__ = 'ro';
         scope.ourvar = scope.ourvar instanceof utils.VDomArray ? utils.vDomToString(scope.ourvar) : scope.ourvar;
         c1.push({text: scope.ourvar});
         scope = _origScope3;
@@ -3243,7 +3349,8 @@ exports[`t-set t-set, t-if, and mix of expression/body lookup, 1 2`] = `
     }
     if (scope.ourvar != null) {
         let _origScope3 = scope;
-        scope = Object.assign(Object.create(context), scope);
+        scope = Object.create(scope);
+        scope.__access_mode__ = 'ro';
         scope.ourvar = scope.ourvar instanceof utils.VDomArray ? utils.vDomToString(scope.ourvar) : scope.ourvar;
         c1.push({text: scope.ourvar});
         scope = _origScope3;
@@ -3271,7 +3378,8 @@ exports[`t-set t-set, t-if, and mix of expression/body lookup, 2 1`] = `
     }
     if (scope.ourvar != null) {
         let _origScope3 = scope;
-        scope = Object.assign(Object.create(context), scope);
+        scope = Object.create(scope);
+        scope.__access_mode__ = 'ro';
         scope.ourvar = scope.ourvar instanceof utils.VDomArray ? utils.vDomToString(scope.ourvar) : scope.ourvar;
         c1.push({text: scope.ourvar});
         scope = _origScope3;
@@ -3299,7 +3407,8 @@ exports[`t-set t-set, t-if, and mix of expression/body lookup, 2 2`] = `
     }
     if (scope.ourvar != null) {
         let _origScope3 = scope;
-        scope = Object.assign(Object.create(context), scope);
+        scope = Object.create(scope);
+        scope.__access_mode__ = 'ro';
         scope.ourvar = scope.ourvar instanceof utils.VDomArray ? utils.vDomToString(scope.ourvar) : scope.ourvar;
         c1.push({text: scope.ourvar});
         scope = _origScope3;
@@ -3325,7 +3434,8 @@ exports[`t-set value priority 1`] = `
     }
     if (scope.value != null) {
         let _origScope3 = scope;
-        scope = Object.assign(Object.create(context), scope);
+        scope = Object.create(scope);
+        scope.__access_mode__ = 'ro';
         scope.value = scope.value instanceof utils.VDomArray ? utils.vDomToString(scope.value) : scope.value;
         c1.push({text: scope.value});
         scope = _origScope3;
diff --git a/tests/qweb/qweb.test.ts b/tests/qweb/qweb.test.ts
index 6e95ab76..e5d75b88 100644
--- a/tests/qweb/qweb.test.ts
+++ b/tests/qweb/qweb.test.ts
@@ -944,6 +944,35 @@ describe("t-call (template calling", () => {
     expect(recursiveFn.toString()).toMatchSnapshot();
   });
 
+  test("recursive template, part 4: with t-set recursive index", () => {
+    qweb.addTemplates(`
+        <templates>
+            <div t-name="Parent">
+                <t t-call="nodeTemplate">
+                    <t t-set="recursive_idx" t-value="1"/>
+                    <t t-set="node" t-value="root"/>
+                </t>
+            </div>
+            <div t-name="nodeTemplate">
+                <t t-set="recursive_idx" t-value="recursive_idx + 1"/>
+                <p><t t-esc="node.val"/> <t t-esc="recursive_idx"/></p>
+                <t t-foreach="node.children or []" t-as="subtree">
+                    <t t-call="nodeTemplate">
+                        <t t-set="node" t-value="subtree"/>
+                    </t>
+                </t>
+            </div>
+
+        </templates>
+    `);
+    const root = { val: "a", children: [{ val: "b", children: [{ val: "c" , children: [{val: "d"}] }] }] };
+    const expected =
+      "<div><div><p>a 2</p><div><p>b 3</p><div><p>c 4</p><div><p>d 5</p></div></div></div></div></div>";
+    expect(renderToString(qweb, "Parent", { root })).toBe(expected);
+    const recursiveFn = Object.values(qweb.subTemplates)[0] as any;
+    expect(recursiveFn.toString()).toMatchSnapshot();
+  });
+
   test("t-call, global templates", () => {
     QWeb.registerTemplate("abcd", '<div><t t-call="john"/></div>');
     qweb.addTemplate("john", `<span>desk</span>`);