diff --git a/src/qweb/base_directives.ts b/src/qweb/base_directives.ts
index a91fa1e4..c13f75b5 100644
--- a/src/qweb/base_directives.ts
+++ b/src/qweb/base_directives.ts
@@ -128,7 +128,12 @@ QWeb.addDirective({
     qwebvar.expr = `scope.${variable}`;
     if (value) {
       const formattedValue = ctx.formatExpression(value);
-      ctx.addLine(`${qwebvar.expr} = ${formattedValue};`);
+      let scopeExpr = `scope`;
+      if (ctx.protectedScopeNumber) {
+        ctx.rootContext.shouldDefineUtils = true;
+        scopeExpr = `utils.getScope(scope, '${variable}')`;
+      }
+      ctx.addLine(`${scopeExpr}.${variable} = ${formattedValue};`);
       qwebvar.value = formattedValue;
     }
 
@@ -313,7 +318,7 @@ QWeb.addDirective({
     ctx.addLine(`_${valuesID} = Object.values(_${arrayID});`);
     ctx.closeIf();
     ctx.addLine(`let _length${keysID} = _${keysID}.length;`);
-    let varsID = ctx.startProtectScope();
+    let varsID = ctx.startProtectScope(true);
     const loopVar = `i${ctx.loopNumber}`;
     ctx.addLine(`for (let ${loopVar} = 0; ${loopVar} < _length${keysID}; ${loopVar}++) {`);
     ctx.indent();
diff --git a/src/qweb/compilation_context.ts b/src/qweb/compilation_context.ts
index 0abceb5e..625a3f71 100644
--- a/src/qweb/compilation_context.ts
+++ b/src/qweb/compilation_context.ts
@@ -17,6 +17,7 @@ export class CompilationContext {
   rootContext: CompilationContext;
   shouldDefineParent: boolean = false;
   shouldDefineScope: boolean = false;
+  protectedScopeNumber: number = 0;
   shouldDefineQWeb: boolean = false;
   shouldDefineUtils: boolean = false;
   shouldDefineRefs: boolean = false;
@@ -173,14 +174,17 @@ export class CompilationContext {
     let r = s.replace(/\{\{.*?\}\}/g, s => "${" + this.formatExpression(s.slice(2, -2)) + "}");
     return "`" + r + "`";
   }
-  startProtectScope(): number {
+  startProtectScope(codeBlock?: boolean): number {
     const protectID = this.generateID();
+    this.rootContext.protectedScopeNumber++;
     this.rootContext.shouldDefineScope = true;
+    const scopeExpr = codeBlock ? `Object.create(scope);` : `Object.assign(Object.create(context), scope);`;
     this.addLine(`let _origScope${protectID} = scope;`);
-    this.addLine(`scope = Object.assign(Object.create(context), scope);`);
+    this.addLine(`scope = ${scopeExpr}`);
     return protectID;
   }
   stopProtectScope(protectID: number) {
+    this.rootContext.protectedScopeNumber--;
     this.addLine(`scope = _origScope${protectID};`);
   }
-}
+}
\ No newline at end of file
diff --git a/src/qweb/qweb.ts b/src/qweb/qweb.ts
index f95d1c58..ec32ef81 100644
--- a/src/qweb/qweb.ts
+++ b/src/qweb/qweb.ts
@@ -86,6 +86,10 @@ interface Utils {
   [key: string]: any;
 }
 
+function isComponent(obj) {
+  return obj && obj.hasOwnProperty("__owl__");
+}
+
 const UTILS: Utils = {
   zero: Symbol("zero"),
   toObj(expr) {
@@ -122,10 +126,21 @@ const UTILS: Utils = {
       .join("");
   },
   getComponent(obj) {
-    while (obj && !obj.hasOwnProperty("__owl__")) {
+    while (obj && !isComponent(obj)) {
       obj = obj.__proto__;
     }
     return obj;
+  },
+  getScope(obj, property: string) {
+    const obj0 = obj;
+    while (obj && !obj.hasOwnProperty(property)) {
+      const newObj = obj.__proto__;
+      if (!newObj || isComponent(newObj)) {
+        return obj0;
+      }
+      obj = newObj;
+    }
+    return obj;
   }
 };
 
diff --git a/tests/component/__snapshots__/component.test.ts.snap b/tests/component/__snapshots__/component.test.ts.snap
index be30c7c3..d78d0b70 100644
--- a/tests/component/__snapshots__/component.test.ts.snap
+++ b/tests/component/__snapshots__/component.test.ts.snap
@@ -58,7 +58,7 @@ exports[`basic widget properties reconciliation alg works for t-foreach in t-for
     }
     let _length3 = _3.length;
     let _origScope5 = scope;
-    scope = Object.assign(Object.create(context), scope);
+    scope = Object.create(scope);
     for (let i1 = 0; i1 < _length3; i1++) {
         scope.section_first = i1 === 0
         scope.section_last = i1 === _length3 - 1
@@ -75,7 +75,7 @@ exports[`basic widget properties reconciliation alg works for t-foreach in t-for
         }
         let _length7 = _7.length;
         let _origScope9 = scope;
-        scope = Object.assign(Object.create(context), scope);
+        scope = Object.create(scope);
         for (let i2 = 0; i2 < _length7; i2++) {
             scope.blip_first = i2 === 0
             scope.blip_last = i2 === _length7 - 1
@@ -432,7 +432,7 @@ exports[`composition sub components with some state rendered in a loop 1`] = `
     }
     let _length3 = _3.length;
     let _origScope5 = scope;
-    scope = Object.assign(Object.create(context), scope);
+    scope = Object.create(scope);
     for (let i1 = 0; i1 < _length3; i1++) {
         scope.number_first = i1 === 0
         scope.number_last = i1 === _length3 - 1
@@ -587,6 +587,58 @@ exports[`dynamic t-props basic use 1`] = `
 }"
 `;
 
+exports[`other directives with t-component slot setted value (with t-set) not accessible with t-esc 1`] = `
+"function anonymous(context, extra
+) {
+    // Template name: \\"__template__2\\"
+    let utils = this.constructor.utils;
+    let QWeb = this.constructor;
+    let parent = context;
+    let scope = Object.create(context);
+    let h = this.h;
+    let c1 = [], p1 = {key:1};
+    let vn1 = h('div', p1, c1);
+    scope.iter = 'source';
+    let c2 = [], p2 = {key:2};
+    let vn2 = h('p', p2, c2);
+    c1.push(vn2);
+    if (scope.iter != null) {
+        c2.push({text: scope.iter});
+    }
+    // Component 'ChildWidget'
+    let w3 = '__4__' in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap['__4__']] : false;
+    let props3 = {};
+    if (w3 && w3.__owl__.currentFiber && !w3.__owl__.vnode) {
+        w3.destroy();
+        w3 = false;
+    }
+    if (w3) {
+        w3.__updateProps(props3, extra.fiber, Object.assign(Object.create(context), scope));
+        let pvnode = w3.__owl__.pvnode;
+        c1.push(pvnode);
+    } else {
+        let componentKey3 = \`ChildWidget\`;
+        let W3 = context.constructor.components[componentKey3] || QWeb.components[componentKey3]|| scope['ChildWidget'];
+        if (!W3) {throw new Error('Cannot find the definition of component \\"' + componentKey3 + '\\"')}
+        w3 = new W3(parent, props3);
+        parent.__owl__.cmap['__4__'] = w3.__owl__.id;
+        w3.__owl__.slotId = 1;
+        let fiber = w3.__prepare(extra.fiber, Object.assign(Object.create(context), scope), () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; });
+        let pvnode = h('dummy', {key: '__4__', hook: {remove() {},destroy(vn) {w3.destroy();}}});
+        c1.push(pvnode);
+        w3.__owl__.pvnode = pvnode;
+    }
+    w3.__owl__.parentLastFiberId = extra.fiber.id;
+    let c5 = [], p5 = {key:5};
+    let vn5 = h('p', p5, c5);
+    c1.push(vn5);
+    if (scope.iter != null) {
+        c5.push({text: scope.iter});
+    }
+    return vn1;
+}"
+`;
+
 exports[`other directives with t-component t-on with getter as handler 1`] = `
 "function anonymous(context, extra
 ) {
@@ -1017,6 +1069,195 @@ exports[`other directives with t-component t-on with stop and/or prevent modifie
 }"
 `;
 
+exports[`other directives with t-component t-set can't alter component 1`] = `
+"function anonymous(context, extra
+) {
+    // Template name: \\"__template__1\\"
+    let scope = Object.create(context);
+    let h = this.h;
+    let c1 = [], p1 = {key:1};
+    let vn1 = h('div', p1, c1);
+    let c2 = [], p2 = {key:2};
+    let vn2 = h('p', p2, c2);
+    c1.push(vn2);
+    let _3 = scope['iter'];
+    if (_3 != null) {
+        c2.push({text: _3});
+    }
+    scope.iter = 5;
+    let c4 = [], p4 = {key:4};
+    let vn4 = h('p', p4, c4);
+    c1.push(vn4);
+    if (scope.iter != null) {
+        c4.push({text: scope.iter});
+    }
+    return vn1;
+}"
+`;
+
+exports[`other directives with t-component t-set can't alter from within callee 1`] = `
+"function anonymous(context, extra
+) {
+    // Template name: \\"__template__1\\"
+    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);
+    scope.iter = 'source';
+    let c2 = [], p2 = {key:2};
+    let vn2 = h('p', p2, c2);
+    c1.push(vn2);
+    if (scope.iter != null) {
+        c2.push({text: scope.iter});
+    }
+    this.subTemplates['ChildWidget'].call(this, Object.assign(Object.create(context), scope), Object.assign({}, extra, {parentNode: c1, parent: utils.getComponent(context)}));
+    let c4 = [], p4 = {key:4};
+    let vn4 = h('p', p4, c4);
+    c1.push(vn4);
+    if (scope.iter != null) {
+        c4.push({text: scope.iter});
+    }
+    return vn1;
+}"
+`;
+
+exports[`other directives with t-component t-set can't alter in t-call body 1`] = `
+"function anonymous(context, extra
+) {
+    // Template name: \\"__template__1\\"
+    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);
+    scope.iter = 'source';
+    let c2 = [], p2 = {key:2};
+    let vn2 = h('p', p2, c2);
+    c1.push(vn2);
+    if (scope.iter != null) {
+        c2.push({text: scope.iter});
+    }
+    {
+        let _origScope4 = scope;
+        scope = Object.assign(Object.create(context), scope);
+        {
+            let c__0 = [];
+            utils.getScope(scope, 'iter').iter = 'inCall';
+            scope[utils.zero] = c__0;
+        }
+        this.subTemplates['ChildWidget'].call(this, scope, Object.assign({}, extra, {parentNode: c1, parent: utils.getComponent(context)}));
+        scope = _origScope4;
+    }
+    let c5 = [], p5 = {key:5};
+    let vn5 = h('p', p5, c5);
+    c1.push(vn5);
+    if (scope.iter != null) {
+        c5.push({text: scope.iter});
+    }
+    return vn1;
+}"
+`;
+
+exports[`other directives with t-component t-set not altered by child widget 1`] = `
+"function anonymous(context, extra
+) {
+    // Template name: \\"__template__2\\"
+    let utils = this.constructor.utils;
+    let QWeb = this.constructor;
+    let parent = context;
+    let scope = Object.create(context);
+    let h = this.h;
+    let c1 = [], p1 = {key:1};
+    let vn1 = h('div', p1, c1);
+    scope.iter = 'source';
+    let c2 = [], p2 = {key:2};
+    let vn2 = h('p', p2, c2);
+    c1.push(vn2);
+    if (scope.iter != null) {
+        c2.push({text: scope.iter});
+    }
+    // Component 'ChildWidget'
+    let w3 = '__4__' in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap['__4__']] : false;
+    let props3 = {};
+    if (w3 && w3.__owl__.currentFiber && !w3.__owl__.vnode) {
+        w3.destroy();
+        w3 = false;
+    }
+    if (w3) {
+        w3.__updateProps(props3, extra.fiber, undefined);
+        let pvnode = w3.__owl__.pvnode;
+        c1.push(pvnode);
+    } else {
+        let componentKey3 = \`ChildWidget\`;
+        let W3 = context.constructor.components[componentKey3] || QWeb.components[componentKey3]|| scope['ChildWidget'];
+        if (!W3) {throw new Error('Cannot find the definition of component \\"' + componentKey3 + '\\"')}
+        w3 = new W3(parent, props3);
+        parent.__owl__.cmap['__4__'] = w3.__owl__.id;
+        let fiber = w3.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; });
+        let pvnode = h('dummy', {key: '__4__', hook: {remove() {},destroy(vn) {w3.destroy();}}});
+        c1.push(pvnode);
+        w3.__owl__.pvnode = pvnode;
+    }
+    w3.__owl__.parentLastFiberId = extra.fiber.id;
+    let c5 = [], p5 = {key:5};
+    let vn5 = h('p', p5, c5);
+    c1.push(vn5);
+    if (scope.iter != null) {
+        c5.push({text: scope.iter});
+    }
+    return vn1;
+}"
+`;
+
+exports[`other directives with t-component t-set outside modified in t-foreach 1`] = `
+"function anonymous(context, extra
+) {
+    // Template name: \\"__template__1\\"
+    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);
+    scope.iter = 0;
+    let _2 = scope['state'].values;
+    if (!_2) { throw new Error('QWeb error: Invalid loop expression')}
+    let _3 = _4 = _2;
+    if (!(_2 instanceof Array)) {
+        _3 = Object.keys(_2);
+        _4 = Object.values(_2);
+    }
+    let _length3 = _3.length;
+    let _origScope5 = scope;
+    scope = Object.create(scope);
+    for (let i1 = 0; i1 < _length3; i1++) {
+        scope.val_first = i1 === 0
+        scope.val_last = i1 === _length3 - 1
+        scope.val_index = i1
+        scope.val = _3[i1]
+        scope.val_value = _4[i1]
+        let key1 = scope['val'];
+        let c6 = [], p6 = {key:\`\${key1}_6\`};
+        let vn6 = h('p', p6, c6);
+        c1.push(vn6);
+        c6.push({text: \`InLoop: \`});
+        if (scope.iter != null) {
+            c6.push({text: scope.iter});
+        }
+        utils.getScope(scope, 'iter').iter = scope.iter+1;
+    }
+    scope = _origScope5;
+    let c7 = [], p7 = {key:7};
+    let vn7 = h('p', p7, c7);
+    c1.push(vn7);
+    c7.push({text: \`EndLoop: \`});
+    if (scope.iter != null) {
+        c7.push({text: scope.iter});
+    }
+    return vn1;
+}"
+`;
+
 exports[`random stuff/miscellaneous can inject values in tagged templates 1`] = `
 "function anonymous(context, extra
 ) {
@@ -1093,7 +1334,7 @@ exports[`random stuff/miscellaneous t-on with handler bound to dynamic argument
     }
     let _length3 = _3.length;
     let _origScope5 = scope;
-    scope = Object.assign(Object.create(context), scope);
+    scope = Object.create(scope);
     for (let i1 = 0; i1 < _length3; i1++) {
         scope.item_first = i1 === 0
         scope.item_last = i1 === _length3 - 1
@@ -1342,7 +1583,7 @@ exports[`t-model directive in a t-foreach 1`] = `
     }
     let _length3 = _3.length;
     let _origScope5 = scope;
-    scope = Object.assign(Object.create(context), scope);
+    scope = Object.create(scope);
     for (let i1 = 0; i1 < _length3; i1++) {
         scope.thing_first = i1 === 0
         scope.thing_last = i1 === _length3 - 1
diff --git a/tests/component/__snapshots__/slots.test.ts.snap b/tests/component/__snapshots__/slots.test.ts.snap
index fe1edc2c..e020d99b 100644
--- a/tests/component/__snapshots__/slots.test.ts.snap
+++ b/tests/component/__snapshots__/slots.test.ts.snap
@@ -263,7 +263,7 @@ exports[`t-slot directive slots are rendered with proper context, part 2 2`] = `
     }
     let _length4 = _4.length;
     let _origScope6 = scope;
-    scope = Object.assign(Object.create(context), scope);
+    scope = Object.create(scope);
     for (let i1 = 0; i1 < _length4; i1++) {
         scope.user_first = i1 === 0
         scope.user_last = i1 === _length4 - 1
@@ -360,7 +360,7 @@ exports[`t-slot directive slots are rendered with proper context, part 3 2`] = `
     }
     let _length4 = _4.length;
     let _origScope6 = scope;
-    scope = Object.assign(Object.create(context), scope);
+    scope = Object.create(scope);
     for (let i1 = 0; i1 < _length4; i1++) {
         scope.user_first = i1 === 0
         scope.user_last = i1 === _length4 - 1
@@ -371,7 +371,7 @@ exports[`t-slot directive slots are rendered with proper context, part 3 2`] = `
         let c7 = [], p7 = {key:\`\${key1}_7\`};
         let vn7 = h('li', p7, c7);
         c2.push(vn7);
-        scope.userdescr = 'User '+scope['user'].name;
+        utils.getScope(scope, 'userdescr').userdescr = 'User '+scope['user'].name;
         // Component 'Link'
         let k9 = \`__9__\${key1}__\`;
         let w8 = k9 in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap[k9]] : false;
diff --git a/tests/component/component.test.ts b/tests/component/component.test.ts
index 52ca2a67..c7d2b960 100644
--- a/tests/component/component.test.ts
+++ b/tests/component/component.test.ts
@@ -2670,6 +2670,238 @@ describe("other directives with t-component", () => {
     await nextTick(); // wait for changes triggered in mounted to be applied
     expect(fixture.innerHTML).toBe("<div><span>B0</span><span>B1</span></div>");
   });
+
+  test("t-set outside modified in t-foreach", async () => {
+    class SomeWidget extends Component<any, any> {
+      static template = xml`
+      <div>
+        <t t-set="iter" t-value="0"/>
+        <t t-foreach="state.values" t-as="val" t-key="val">
+          <p>InLoop: <t t-esc="iter"/></p>
+          <t t-set="iter" t-value="iter + 1"/>
+        </t>
+        <p>EndLoop: <t t-esc="iter"/></p>
+      </div>`;
+
+      state = useState({values: ['a', 'b']});
+    }
+    const widget = new SomeWidget();
+    await widget.mount(fixture);
+
+    expect(fixture.innerHTML).toBe("<div><p>InLoop: 0</p><p>InLoop: 1</p><p>EndLoop: 2</p></div>");
+    expect(QWeb.TEMPLATES[SomeWidget.template].fn.toString()).toMatchSnapshot();
+  });
+
+  test("t-set outside modified in t-if", async () => {
+    class SomeWidget extends Component<any, any> {
+      static template = xml`
+      <div>
+        <t t-set="iter" t-value="0"/>
+        <t t-set="flag" t-value="state.flag" />
+        <t t-if="flag === 'if'">
+          <t t-set="iter" t-value="2"/>
+        </t>
+        <t t-elif="flag === 'elif'">
+          <t t-set="iter" t-value="3"/>
+        </t>
+        <t t-else="">
+          <t t-set="iter" t-value="4"/>
+        </t>
+        <p><t t-esc="iter"/></p>
+      </div>`;
+
+      state = {flag: 'if'};
+    }
+    const widget = new SomeWidget();
+    await widget.mount(fixture);
+
+    expect(fixture.innerHTML).toBe("<div><p>2</p></div>");
+    widget.state.flag = 'elif';
+    await widget.render();
+    expect(fixture.innerHTML).toBe("<div><p>3</p></div>");
+    widget.state.flag = 'false';
+    await widget.render();
+    expect(fixture.innerHTML).toBe("<div><p>4</p></div>");
+  });
+
+  test("t-set in t-if", async () => {
+    // Weird that code block within 'if' leaks outside of it
+    // Python does the same   
+    class SomeWidget extends Component<any, any> {
+      static template = xml`
+      <div>
+        <t t-set="flag" t-value="state.flag" />
+        <t t-if="flag === 'if'">
+          <t t-set="iter" t-value="2"/>
+        </t>
+        <t t-elif="flag === 'elif'">
+          <t t-set="iter" t-value="3"/>
+        </t>
+        <t t-else="">
+          <t t-set="iter" t-value="4"/>
+        </t>
+        <p><t t-esc="iter"/></p>
+      </div>`;
+
+      state = {flag: 'if'};
+    }
+    const widget = new SomeWidget();
+    await widget.mount(fixture);
+
+    expect(fixture.innerHTML).toBe("<div><p>2</p></div>");
+    widget.state.flag = 'elif';
+    await widget.render();
+    expect(fixture.innerHTML).toBe("<div><p>3</p></div>");
+    widget.state.flag = 'false';
+    await widget.render();
+    expect(fixture.innerHTML).toBe("<div><p>4</p></div>");
+  });
+
+  test("t-set can't alter component", async () => {
+    class SomeWidget extends Component<any, any> {
+      static template = xml`
+      <div>
+        <p><t t-esc="iter"/></p>
+        <t t-set="iter" t-value="5"/>
+        <p><t t-esc="iter"/></p>
+      </div>`;
+
+      iter = 1;
+    }
+    const widget = new SomeWidget();
+    await widget.mount(fixture);
+
+    expect(fixture.innerHTML).toBe("<div><p>1</p><p>5</p></div>");
+    expect(widget.iter).toBe(1);
+    expect(QWeb.TEMPLATES[SomeWidget.template].fn.toString()).toMatchSnapshot();
+  });
+
+  test("t-set can't alter from within callee", async () => {
+    env.qweb.addTemplate("ChildWidget", `<div><t t-esc="iter"/><t t-set="iter" t-value="'called'"/><t t-esc="iter"/></div>`);
+    class SomeWidget extends Component<any, any> {
+      static template = xml`
+      <div>
+        <t t-set="iter" t-value="'source'"/>
+        <p><t t-esc="iter"/></p>
+        <t t-call="ChildWidget"/>
+        <p><t t-esc="iter"/></p>
+      </div>`;
+    }
+    const widget = new SomeWidget();
+    await widget.mount(fixture);
+
+    expect(fixture.innerHTML).toBe("<div><p>source</p><div>sourcecalled</div><p>source</p></div>");
+    expect(QWeb.TEMPLATES[SomeWidget.template].fn.toString()).toMatchSnapshot();
+  });
+
+  test("t-set can't alter in t-call body", async () => {
+    env.qweb.addTemplate("ChildWidget", `<div><t t-esc="iter"/><t t-set="iter" t-value="'called'"/><t t-esc="iter"/></div>`);
+    class SomeWidget extends Component<any, any> {
+      static template = xml`
+      <div>
+        <t t-set="iter" t-value="'source'"/>
+        <p><t t-esc="iter"/></p>
+        <t t-call="ChildWidget">
+          <t t-set="iter" t-value="'inCall'"/>
+        </t>
+        <p><t t-esc="iter"/></p>
+      </div>`;
+    }
+    const widget = new SomeWidget();
+    await widget.mount(fixture);
+
+    expect(fixture.innerHTML).toBe("<div><p>source</p><div>inCallcalled</div><p>source</p></div>");
+    expect(QWeb.TEMPLATES[SomeWidget.template].fn.toString()).toMatchSnapshot();
+  });
+
+  test("slot setted value (with t-set) not accessible with t-esc", async () => {
+    class ChildWidget extends Component<any, any> {
+      static template = xml`<div><t t-esc="iter"/><t t-set="iter" t-value="'called'"/><t t-esc="iter"/></div>`;
+    }
+    class SomeWidget extends Component<any, any> {
+      static components = { ChildWidget };
+      static template = xml`
+      <div>
+        <t t-set="iter" t-value="'source'"/>
+        <p><t t-esc="iter"/></p>
+        <ChildWidget>
+          <t t-set="iter" t-value="'inCall'"/>
+        </ChildWidget>
+        <p><t t-esc="iter"/></p>
+      </div>`;
+    }
+    const widget = new SomeWidget();
+    await widget.mount(fixture);
+
+    expect(fixture.innerHTML).toBe("<div><p>source</p><div>called</div><p>source</p></div>");
+    expect(QWeb.TEMPLATES[SomeWidget.template].fn.toString()).toMatchSnapshot();
+  });
+
+  test("t-set not altered by child widget", async () => {
+    let child;
+    class ChildWidget extends Component<any, any> {
+      static template = xml`<div><t t-esc="iter"/><t t-set="iter" t-value="'called'"/><t t-esc="iter"/></div>`;
+      iter = 'child';
+      constructor() {
+        super(...arguments);
+        child = this;
+      }
+    }
+    class SomeWidget extends Component<any, any> {
+      static components = { ChildWidget };
+      static template = xml`
+      <div>
+        <t t-set="iter" t-value="'source'"/>
+        <p><t t-esc="iter"/></p>
+        <ChildWidget/>
+        <p><t t-esc="iter"/></p>
+      </div>`;
+    }
+    const widget = new SomeWidget();
+    await widget.mount(fixture);
+
+    expect(fixture.innerHTML).toBe("<div><p>source</p><div>childcalled</div><p>source</p></div>");
+    expect(child.iter).toBe('child');
+    expect(QWeb.TEMPLATES[SomeWidget.template].fn.toString()).toMatchSnapshot();
+  });
+
+  test("t-set outside modified in t-foreach increment-after operator", async () => {
+    class SomeWidget extends Component<any, any> {
+      static template = xml`
+      <div>
+        <t t-set="iter" t-value="0"/>
+        <t t-foreach="state.values" t-as="val" t-key="val">
+          <p>InLoop: <t t-esc="iter"/></p>
+          <t t-set="iter" t-value="iter++"/>
+        </t>
+        <p>EndLoop: <t t-esc="iter"/></p>
+      </div>`;
+
+      state = useState({values: ['a', 'b']});
+    }
+    const widget = new SomeWidget();
+    await widget.mount(fixture);
+    expect(fixture.innerHTML).toBe("<div><p>InLoop: 0</p><p>InLoop: 1</p><p>EndLoop: 0</p></div>");
+  });
+
+  test("t-set outside modified in t-foreach increment-before operator", async () => {
+    class SomeWidget extends Component<any, any> {
+      static template = xml`
+      <div>
+        <t t-set="iter" t-value="0"/>
+        <t t-foreach="state.values" t-as="val" t-key="val">
+          <p>InLoop: <t t-esc="iter"/></p>
+          <t t-set="iter" t-value="++iter"/>
+        </t>
+        <p>EndLoop: <t t-esc="iter"/></p>
+      </div>`;
+
+      state = useState({values: ['a', 'b']});
+    }
+    const widget = new SomeWidget();
+    await widget.mount(fixture);
+    expect(fixture.innerHTML).toBe("<div><p>InLoop: 0</p><p>InLoop: 1</p><p>EndLoop: 1</p></div>");
+  });
 });
 
 describe("random stuff/miscellaneous", () => {
diff --git a/tests/qweb/__snapshots__/qweb.test.ts.snap b/tests/qweb/__snapshots__/qweb.test.ts.snap
index 4026a6f1..7e37322e 100644
--- a/tests/qweb/__snapshots__/qweb.test.ts.snap
+++ b/tests/qweb/__snapshots__/qweb.test.ts.snap
@@ -421,7 +421,7 @@ exports[`foreach does not pollute the rendering context 1`] = `
     }
     let _length3 = _3.length;
     let _origScope5 = scope;
-    scope = Object.assign(Object.create(context), scope);
+    scope = Object.create(scope);
     for (let i1 = 0; i1 < _length3; i1++) {
         scope.item_first = i1 === 0
         scope.item_last = i1 === _length3 - 1
@@ -456,7 +456,7 @@ exports[`foreach iterate on items (on a element node) 1`] = `
     }
     let _length3 = _3.length;
     let _origScope5 = scope;
-    scope = Object.assign(Object.create(context), scope);
+    scope = Object.create(scope);
     for (let i1 = 0; i1 < _length3; i1++) {
         scope.item_first = i1 === 0
         scope.item_last = i1 === _length3 - 1
@@ -494,7 +494,7 @@ exports[`foreach iterate on items 1`] = `
     }
     let _length3 = _3.length;
     let _origScope5 = scope;
-    scope = Object.assign(Object.create(context), scope);
+    scope = Object.create(scope);
     for (let i1 = 0; i1 < _length3; i1++) {
         scope.item_first = i1 === 0
         scope.item_last = i1 === _length3 - 1
@@ -541,7 +541,7 @@ exports[`foreach iterate, dict param 1`] = `
     }
     let _length3 = _3.length;
     let _origScope5 = scope;
-    scope = Object.assign(Object.create(context), scope);
+    scope = Object.create(scope);
     for (let i1 = 0; i1 < _length3; i1++) {
         scope.item_first = i1 === 0
         scope.item_last = i1 === _length3 - 1
@@ -588,7 +588,7 @@ exports[`foreach iterate, position 1`] = `
     }
     let _length3 = _3.length;
     let _origScope5 = scope;
-    scope = Object.assign(Object.create(context), scope);
+    scope = Object.create(scope);
     for (let i1 = 0; i1 < _length3; i1++) {
         scope.elem_first = i1 === 0
         scope.elem_last = i1 === _length3 - 1
@@ -632,7 +632,7 @@ exports[`foreach t-foreach in t-forach 1`] = `
     }
     let _length3 = _3.length;
     let _origScope5 = scope;
-    scope = Object.assign(Object.create(context), scope);
+    scope = Object.create(scope);
     for (let i1 = 0; i1 < _length3; i1++) {
         scope.number_first = i1 === 0
         scope.number_last = i1 === _length3 - 1
@@ -649,7 +649,7 @@ exports[`foreach t-foreach in t-forach 1`] = `
         }
         let _length7 = _7.length;
         let _origScope9 = scope;
-        scope = Object.assign(Object.create(context), scope);
+        scope = Object.create(scope);
         for (let i2 = 0; i2 < _length7; i2++) {
             scope.letter_first = i2 === 0
             scope.letter_last = i2 === _length7 - 1
@@ -692,7 +692,7 @@ exports[`foreach warn if no key in some case 1`] = `
     }
     let _length3 = _3.length;
     let _origScope5 = scope;
-    scope = Object.assign(Object.create(context), scope);
+    scope = Object.create(scope);
     for (let i1 = 0; i1 < _length3; i1++) {
         scope.item_first = i1 === 0
         scope.item_last = i1 === _length3 - 1
@@ -757,7 +757,7 @@ exports[`misc global 1`] = `
     }
     let _length3 = _3.length;
     let _origScope5 = scope;
-    scope = Object.assign(Object.create(context), scope);
+    scope = Object.create(scope);
     for (let i1 = 0; i1 < _length3; i1++) {
         scope.value_first = i1 === 0
         scope.value_last = i1 === _length3 - 1
@@ -782,7 +782,7 @@ exports[`misc global 1`] = `
                     scope = Object.assign(Object.create(context), scope);
                     {
                         let c__0 = [];
-                        scope.foo = 'aaa';
+                        utils.getScope(scope, 'foo').foo = 'aaa';
                         scope[utils.zero] = c__0;
                     }
                     let k14 = \`__14__\${key1}__\`;
@@ -791,7 +791,7 @@ exports[`misc global 1`] = `
                 }
                 let k15 = \`__15__\${key1}__\`;
                 this.subTemplates['_callee-uses-foo'].call(this, Object.assign(Object.create(context), scope), Object.assign({}, extra, {parentNode: c__0, parent: utils.getComponent(context), key: k15}));
-                scope.foo = 'bbb';
+                utils.getScope(scope, 'foo').foo = 'bbb';
                 let k16 = \`__16__\${key1}__\`;
                 this.subTemplates['_callee-uses-foo'].call(this, Object.assign(Object.create(context), scope), Object.assign({}, extra, {parentNode: c__0, parent: utils.getComponent(context), key: k16}));
                 scope[utils.zero] = c__0;
@@ -1241,7 +1241,7 @@ exports[`t-call (template calling recursive template, part 2 1`] = `
         scope = Object.assign(Object.create(context), scope);
         {
             let c__0 = [];
-            scope.node = scope['root'];
+            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__'}));
@@ -1279,7 +1279,7 @@ exports[`t-call (template calling recursive template, part 2 2`] = `
     }
     let _length6 = _6.length;
     let _origScope8 = scope;
-    scope = Object.assign(Object.create(context), scope);
+    scope = Object.create(scope);
     for (let i1 = 0; i1 < _length6; i1++) {
         scope.subtree_first = i1 === 0
         scope.subtree_last = i1 === _length6 - 1
@@ -1292,7 +1292,7 @@ exports[`t-call (template calling recursive template, part 2 2`] = `
             scope = Object.assign(Object.create(context), scope);
             {
                 let c__0 = [];
-                scope.node = scope['subtree'];
+                utils.getScope(scope, 'node').node = scope['subtree'];
                 scope[utils.zero] = c__0;
             }
             let k10 = \`__10__\${key0}__\${key1}__\`;
@@ -1318,7 +1318,7 @@ exports[`t-call (template calling recursive template, part 3 1`] = `
         scope = Object.assign(Object.create(context), scope);
         {
             let c__0 = [];
-            scope.node = scope['root'];
+            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__'}));
@@ -1356,7 +1356,7 @@ exports[`t-call (template calling recursive template, part 3 2`] = `
     }
     let _length6 = _6.length;
     let _origScope8 = scope;
-    scope = Object.assign(Object.create(context), scope);
+    scope = Object.create(scope);
     for (let i1 = 0; i1 < _length6; i1++) {
         scope.subtree_first = i1 === 0
         scope.subtree_last = i1 === _length6 - 1
@@ -1369,7 +1369,7 @@ exports[`t-call (template calling recursive template, part 3 2`] = `
             scope = Object.assign(Object.create(context), scope);
             {
                 let c__0 = [];
-                scope.node = scope['subtree'];
+                utils.getScope(scope, 'node').node = scope['subtree'];
                 scope[utils.zero] = c__0;
             }
             let k10 = \`__10__\${key0}__\${key1}__\`;
@@ -1395,7 +1395,7 @@ exports[`t-call (template calling scoped parameters 1`] = `
         scope = Object.assign(Object.create(context), scope);
         {
             let c__0 = [];
-            scope.foo = 42;
+            utils.getScope(scope, 'foo').foo = 42;
             scope[utils.zero] = c__0;
         }
         this.subTemplates['_basic-callee'].call(this, scope, Object.assign({}, extra, {parentNode: c1, parent: utils.getComponent(context), key: '__3__'}));
@@ -1456,7 +1456,7 @@ exports[`t-call (template calling t-call with t-set inside and outside 1`] = `
     }
     let _length3 = _3.length;
     let _origScope5 = scope;
-    scope = Object.assign(Object.create(context), scope);
+    scope = Object.create(scope);
     for (let i1 = 0; i1 < _length3; i1++) {
         scope.v_first = i1 === 0
         scope.v_last = i1 === _length3 - 1
@@ -1464,13 +1464,13 @@ exports[`t-call (template calling t-call with t-set inside and outside 1`] = `
         scope.v = _3[i1]
         scope.v_value = _4[i1]
         let key1 = i1;
-        scope.val = scope['v'].val;
+        utils.getScope(scope, 'val').val = scope['v'].val;
         {
             let _origScope8 = scope;
             scope = Object.assign(Object.create(context), scope);
             {
                 let c__0 = [];
-                scope.val3 = scope.val*3;
+                utils.getScope(scope, 'val3').val3 = scope.val*3;
                 scope[utils.zero] = c__0;
             }
             let k9 = \`__9__\${key1}__\`;
@@ -1517,7 +1517,7 @@ exports[`t-call (template calling t-call, conditional and t-set in t-call body 1
             scope = Object.assign(Object.create(context), scope);
             {
                 let c__0 = [];
-                scope.v = 'success';
+                utils.getScope(scope, 'v').v = 'success';
                 scope[utils.zero] = c__0;
             }
             this.subTemplates['callee2'].call(this, scope, Object.assign({}, extra, {parentNode: c1, parent: utils.getComponent(context), key: '__7__'}));
@@ -1580,7 +1580,7 @@ exports[`t-call (template calling with unused setbody 1`] = `
         scope = Object.assign(Object.create(context), scope);
         {
             let c__0 = [];
-            scope.qux = 3;
+            utils.getScope(scope, 'qux').qux = 3;
             scope[utils.zero] = c__0;
         }
         result = []
@@ -1631,7 +1631,7 @@ exports[`t-call (template calling with used set body 1`] = `
         scope = Object.assign(Object.create(context), scope);
         {
             let c__0 = [];
-            scope.foo = 'ok';
+            utils.getScope(scope, 'foo').foo = 'ok';
             scope[utils.zero] = c__0;
         }
         this.subTemplates['_callee-uses-foo'].call(this, scope, Object.assign({}, extra, {parentNode: c1, parent: utils.getComponent(context), key: '__4__'}));
@@ -2156,7 +2156,7 @@ exports[`t-key t-key directive in a list 1`] = `
     }
     let _length3 = _3.length;
     let _origScope5 = scope;
-    scope = Object.assign(Object.create(context), scope);
+    scope = Object.create(scope);
     for (let i1 = 0; i1 < _length3; i1++) {
         scope.beer_first = i1 === 0
         scope.beer_last = i1 === _length3 - 1
@@ -2260,7 +2260,7 @@ exports[`t-on can bind handlers with loop variable as argument 1`] = `
     }
     let _length3 = _3.length;
     let _origScope5 = scope;
-    scope = Object.assign(Object.create(context), scope);
+    scope = Object.create(scope);
     for (let i1 = 0; i1 < _length3; i1++) {
         scope.action_first = i1 === 0
         scope.action_last = i1 === _length3 - 1
@@ -2517,7 +2517,7 @@ exports[`t-on t-on with prevent modifier in t-foreach 1`] = `
     }
     let _length3 = _3.length;
     let _origScope5 = scope;
-    scope = Object.assign(Object.create(context), scope);
+    scope = Object.create(scope);
     for (let i1 = 0; i1 < _length3; i1++) {
         scope.project_first = i1 === 0
         scope.project_last = i1 === _length3 - 1
@@ -2763,7 +2763,7 @@ exports[`t-ref refs in a loop 1`] = `
     }
     let _length3 = _3.length;
     let _origScope5 = scope;
-    scope = Object.assign(Object.create(context), scope);
+    scope = Object.create(scope);
     for (let i1 = 0; i1 < _length3; i1++) {
         scope.item_first = i1 === 0
         scope.item_last = i1 === _length3 - 1
@@ -2990,6 +2990,7 @@ exports[`t-set t-set should reuse variable if possible 1`] = `
 "function anonymous(context, extra
 ) {
     // Template name: \\"test\\"
+    let utils = this.constructor.utils;
     let scope = Object.create(context);
     let h = this.h;
     let c1 = [], p1 = {key:1};
@@ -3004,7 +3005,7 @@ exports[`t-set t-set should reuse variable if possible 1`] = `
     }
     let _length3 = _3.length;
     let _origScope5 = scope;
-    scope = Object.assign(Object.create(context), scope);
+    scope = Object.create(scope);
     for (let i1 = 0; i1 < _length3; i1++) {
         scope.elem_first = i1 === 0
         scope.elem_last = i1 === _length3 - 1
@@ -3022,7 +3023,7 @@ exports[`t-set t-set should reuse variable if possible 1`] = `
         if (scope.v != null) {
             c7.push({text: scope.v});
         }
-        scope.v = scope['elem'];
+        utils.getScope(scope, 'v').v = scope['elem'];
     }
     scope = _origScope5;
     return vn1;