diff --git a/htdocs/projet/tasks/time.php b/htdocs/projet/tasks/time.php
index 523f93e97e496..aad0471027bd3 100644
--- a/htdocs/projet/tasks/time.php
+++ b/htdocs/projet/tasks/time.php
@@ -2119,6 +2119,9 @@ function setDetailVisibility() {
 				break;
 			}
 
+			// Line is invoiced if it has an invoice_id
+			$invoiced = $task_time->invoice_id ? true : false;
+
 			$date1 = $db->jdate($task_time->element_date);
 			$date2 = $db->jdate($task_time->element_datehour);
 
@@ -2156,7 +2159,18 @@ function setDetailVisibility() {
 								$selected = 1;
 							}
 							print ' ';
-							print '<input id="cb' . $task_time->rowid . '" class="flat checkforselect marginleftonly" type="checkbox" name="toselect[]" value="' . $task_time->rowid . '"' . ($selected ? ' checked="checked"' : '') . '>';
+
+							// Disable select if task not billable or already invoiced
+							$disabled = (intval($task_time->billable) != 1 || $invoiced);
+							$ctrl = '<input '.($disabled ? 'disabled' : '').' id="cb' . $task_time->rowid . '" class="flat checkforselect marginleftonly" type="checkbox" name="toselect[]" value="' . $task_time->rowid . '"' . ($selected ? ' checked="checked"' : '') . '>';
+							if ($disabled) {
+								// If disabled, a dbl-click very close outside the control
+								// will re-enable it, so that user is not blocked if needed.
+								print '<span id="cbsp'. $task_time->rowid . '">'.$ctrl.'</span>';
+								print '<script>$("#cbsp' . $task_time->rowid . '").dblclick(()=>{ $("#cb' . $task_time->rowid . '").removeAttr("disabled") })</script>';
+							} else {
+								print $ctrl;
+							}
 						}
 					}
 				}
@@ -2426,7 +2440,6 @@ function setDetailVisibility() {
 			}
 
 			// Invoiced
-			$invoiced = false;
 			if (!empty($arrayfields['valuebilled']['checked'])) {
 				print '<td class="center">'; // invoice_id and invoice_line_id
 				if (!getDolGlobalString('PROJECT_HIDE_TASKS') && getDolGlobalString('PROJECT_BILL_TIME_SPENT')) {
@@ -2506,6 +2519,7 @@ function setDetailVisibility() {
 								$selected = 1;
 							}
 							print '&nbsp;';
+
 							// Disable select if task not billable or already invoiced
 							$disabled = (intval($task_time->billable) != 1 || $invoiced);
 							$ctrl = '<input '.($disabled ? 'disabled' : '').' id="cb' . $task_time->rowid . '" class="flat checkforselect marginleftonly" type="checkbox" name="toselect[]" value="' . $task_time->rowid . '"' . ($selected ? ' checked="checked"' : '') . '>';