diff --git a/htdocs/core/lib/functions.lib.php b/htdocs/core/lib/functions.lib.php
index 62b72c81579..4f1b14336b9 100644
--- a/htdocs/core/lib/functions.lib.php
+++ b/htdocs/core/lib/functions.lib.php
@@ -8252,15 +8252,30 @@ function getCommonSubstitutionArray($outputlangs, $onlykey = 0, $exclude = null,
 				$substitutionarray['__ATTENDEE_LASTNAME__'] = isset($object->lastname) ? $object->lastname : '';
 			}
 
+			$project = null;
 			if (is_object($object->project)) {
-				$substitutionarray['__PROJECT_ID__'] = (is_object($object->project) ? $object->project->id : '');
-				$substitutionarray['__PROJECT_REF__'] = (is_object($object->project) ? $object->project->ref : '');
-				$substitutionarray['__PROJECT_NAME__'] = (is_object($object->project) ? $object->project->title : '');
+				$project = $object->project;
+			} elseif (is_object($object->projet)) { // Deprecated, for backward compatibility
+				$project = $object->projet;
 			}
-			if (is_object($object->projet)) {	// Deprecated, for backward compatibility
-				$substitutionarray['__PROJECT_ID__'] = (is_object($object->projet) ? $object->projet->id : '');
-				$substitutionarray['__PROJECT_REF__'] = (is_object($object->projet) ? $object->projet->ref : '');
-				$substitutionarray['__PROJECT_NAME__'] = (is_object($object->projet) ? $object->projet->title : '');
+			if ($project) {
+				$substitutionarray['__PROJECT_ID__'] = $project->id;
+				$substitutionarray['__PROJECT_REF__'] = $project->ref;
+				$substitutionarray['__PROJECT_NAME__'] = $project->title;
+			} else {
+				// can substitute variables for project : uses lazy load in "make_substitutions" method
+				$project_id = 0;
+				if ($object->fk_project > 0) {
+					$project_id = $object->fk_project;
+				} elseif ($object->fk_projet > 0) {
+					$project_id = $object->fk_project;
+				}
+				if ($project_id > 0) {
+					// path:class:method:id
+					$substitutionarray['__PROJECT_ID__@lazyload'] = '/projet/class/project.class.php:Project:fetchAndSetSubstitution:' . $project_id;
+					$substitutionarray['__PROJECT_REF__@lazyload'] = '/projet/class/project.class.php:Project:fetchAndSetSubstitution:' . $project_id;
+					$substitutionarray['__PROJECT_NAME__@lazyload'] = '/projet/class/project.class.php:Project:fetchAndSetSubstitution:' . $project_id;
+				}
 			}
 			if (is_object($object) && $object->element == 'project') {
 				$substitutionarray['__PROJECT_NAME__'] = $object->title;
@@ -8580,7 +8595,7 @@ function getCommonSubstitutionArray($outputlangs, $onlykey = 0, $exclude = null,
  */
 function make_substitutions($text, $substitutionarray, $outputlangs = null, $converttextinhtmlifnecessary = 0)
 {
-	global $conf, $langs;
+	global $conf, $db, $langs;
 
 	if (!is_array($substitutionarray)) {
 		return 'ErrorBadParameterSubstitutionArrayWhenCalling_make_substitutions';
@@ -8698,6 +8713,53 @@ function make_substitutions($text, $substitutionarray, $outputlangs = null, $con
 	$valuetouseforsubstitution = $tmpobj->$method($id, '__XXX__');
 	And make the replacement of "__XXX__@lazyload" with $valuetouseforsubstitution
 	*/
+	$memory_object_list = array();
+	foreach ($substitutionarray as $key => $value) {
+		$lazy_load_arr = array();
+		if (preg_match('/(__[A-Z\_]+__)@lazyload$/', $key, $lazy_load_arr)) {
+			if (isset($lazy_load_arr[1]) && !empty($lazy_load_arr[1])) {
+				$key_to_substitute = $lazy_load_arr[1];
+				if (preg_match('/' . preg_quote($key_to_substitute, '/') . '/', $text)) {
+					$param_arr = explode(':', $value);
+					// path:class:method:id
+					if (count($param_arr) == 4) {
+						$path = $param_arr[0];
+						$class = $param_arr[1];
+						$method = $param_arr[2];
+						$id = (int) $param_arr[3];
+
+						// load class file and init object list in memory
+						if (!isset($memory_object_list[$class])) {
+							if (dol_is_file(DOL_DOCUMENT_ROOT . $path)) {
+								require_once DOL_DOCUMENT_ROOT . $path;
+								if (class_exists($class)) {
+									$memory_object_list[$class] = array(
+										'list' => array(),
+									);
+								}
+							}
+						}
+
+						// fetch object and set substitution
+						if (isset($memory_object_list[$class]) && isset($memory_object_list[$class]['list'])) {
+							if (method_exists($class, $method)) {
+								if (!isset($memory_object_list[$class]['list'][$id])) {
+									$tmpobj = new $class($db);
+									$valuetouseforsubstitution = $tmpobj->$method($id, $key_to_substitute);
+									$memory_object_list[$class]['list'][$id] = $tmpobj;
+								} else {
+									$tmpobj = $memory_object_list[$class]['list'][$id];
+									$valuetouseforsubstitution = $tmpobj->$method($id, $key_to_substitute, true);
+								}
+
+								$text = str_replace("$key_to_substitute", "$valuetouseforsubstitution", $text); // We must keep the " to work when value is 123.5 for example
+							}
+						}
+					}
+				}
+			}
+		}
+	}
 
 	return $text;
 }
diff --git a/htdocs/projet/class/project.class.php b/htdocs/projet/class/project.class.php
index 470c940f10f..38abd37a7ed 100644
--- a/htdocs/projet/class/project.class.php
+++ b/htdocs/projet/class/project.class.php
@@ -776,6 +776,38 @@ class Project extends CommonObject
 		}
 	}
 
+	/**
+	 * Fetch object and substitute key
+	 *
+	 * @param	int			$id					Project id
+	 * @param 	string		$key				Key to substitute
+	 * @param 	bool		$fetched			[=false] Not already fetched
+	 * @return 	string		Substitute key
+	 */
+	public function fetchAndSetSubstitution($id, $key, $fetched = false)
+	{
+		$substitution = '';
+
+		if ($fetched === false) {
+			$res = $this->fetch($id);
+			if ($res > 0) {
+				$fetched = true;
+			}
+		}
+
+		if ($fetched === true) {
+			if ($key == '__PROJECT_ID__') {
+				$substitution = ($this->id > 0 ? $this->id : '');
+			} elseif ($key == '__PROJECT_REF__') {
+				$substitution = $this->ref;
+			} elseif ($key == '__PROJECT_NAME__') {
+				$substitution = $this->title;
+			}
+		}
+
+		return $substitution;
+	}
+
 	// phpcs:disable PEAR.NamingConventions.ValidFunctionName.ScopeNotCamelCaps
 	/**
 	 * 	Return list of elements for type, linked to a project