diff --git a/addons/web/static/src/views/list/list_renderer.js b/addons/web/static/src/views/list/list_renderer.js
index 34586292319..da45ebb672a 100644
--- a/addons/web/static/src/views/list/list_renderer.js
+++ b/addons/web/static/src/views/list/list_renderer.js
@@ -203,7 +203,7 @@ export class ListRenderer extends Component {
         }
 
         const table = this.tableRef.el;
-        const headers = [...table.querySelectorAll("thead th")];
+        const headers = [...table.querySelectorAll("thead th:not(.o_list_record_remove_header)")];
 
         if (!this.columnWidths || !this.columnWidths.length) {
             // no column widths to restore
@@ -333,6 +333,17 @@ export class ListRenderer extends Component {
         return this.props.list.fields;
     }
 
+    get nbCols() {
+        let nbCols = this.state.columns.length;
+        if (this.hasSelectors) {
+            nbCols++;
+        }
+        if (this.props.activeActions && this.props.activeActions.onDelete) {
+            nbCols++;
+        }
+        return nbCols;
+    }
+
     canUseFormatter(column, record) {
         return (
             !record.isInEdition && !column.widget && record.fields[column.name].type !== "boolean"
diff --git a/addons/web/static/src/views/list/list_renderer.xml b/addons/web/static/src/views/list/list_renderer.xml
index 6cadfaa080d..465f9a90630 100644
--- a/addons/web/static/src/views/list/list_renderer.xml
+++ b/addons/web/static/src/views/list/list_renderer.xml
@@ -75,7 +75,7 @@
             </t>
             <tr t-if="displayRowCreates">
                 <td t-if="withHandleColumn"/>
-                <td t-att-colspan="state.columns.length + 1"
+                <td t-att-colspan="withHandleColumn ? nbCols - 1 : nbCols"
                     class="o_field_x2many_list_row_add"
                     t-on-keydown.synthetic="(ev) => this.onCellKeydown(ev, null)"
                 >
@@ -105,7 +105,7 @@
             </tr>
             <t t-if="!props.list.isGrouped">
                 <tr t-foreach="getEmptyRowIds" t-as="emptyRowId" t-key="emptyRowId">
-                    <td t-att-colspan="state.columns.length + 1">&#8203;</td>
+                    <td t-att-colspan="nbCols">&#8203;</td>
                 </tr>
             </t>
         </t>
@@ -119,7 +119,7 @@
                     <tr t-if="!group.list.isGrouped and props.editable and props.activeActions['create']">
                         <td t-if="hasSelectors"/>
                         <td
-                            t-att-colspan="state.columns.length + 1"
+                            t-att-colspan="hasSelector ? nbCols - 1 : nbCols"
                             class="o_group_field_row_add"
                         >
                             <a href="#"
diff --git a/addons/web/static/tests/views/list_view_tests.js b/addons/web/static/tests/views/list_view_tests.js
index e5f47041df6..b5e08e2e8a6 100644
--- a/addons/web/static/tests/views/list_view_tests.js
+++ b/addons/web/static/tests/views/list_view_tests.js
@@ -3123,6 +3123,35 @@ QUnit.module("Views", (hooks) => {
         }
     );
 
+    QUnit.test("colspan of empty lines is correct in readonly and edit", async function (assert) {
+        serverData.models.foo.fields.foo_o2m = {
+            string: "Foo O2M",
+            type: "one2many",
+            relation: "foo",
+        };
+        await makeView({
+            type: "form",
+            resModel: "foo",
+            serverData,
+            resId: 1,
+            mode: "readonly",
+            arch: `
+                    <form>
+                        <sheet>
+                            <field name="foo_o2m">
+                                <tree editable="bottom">
+                                    <field name="int_field"/>
+                                </tree>
+                            </field>
+                        </sheet>
+                    </form>`,
+        });
+        assert.strictEqual(target.querySelector("tbody td").getAttribute("colspan"), "1");
+        await clickEdit(target);
+        // in edit mode, the delete action is available and the empty lines should cover that col
+        assert.strictEqual(target.querySelector("tbody td").getAttribute("colspan"), "2");
+    });
+
     QUnit.test(
         "width of some fields should be hardcoded if no data, and list initially invisible",
         async function (assert) {