diff --git a/htdocs/core/modules/propale/doc/doc_generic_proposal_odt.modules.php b/htdocs/core/modules/propale/doc/doc_generic_proposal_odt.modules.php
index 636bf4c4f7f..66e2f3c8312 100644
--- a/htdocs/core/modules/propale/doc/doc_generic_proposal_odt.modules.php
+++ b/htdocs/core/modules/propale/doc/doc_generic_proposal_odt.modules.php
@@ -31,6 +31,7 @@ require_once DOL_DOCUMENT_ROOT.'/core/lib/company.lib.php';
 require_once DOL_DOCUMENT_ROOT.'/core/lib/functions2.lib.php';
 require_once DOL_DOCUMENT_ROOT.'/core/lib/files.lib.php';
 require_once DOL_DOCUMENT_ROOT.'/core/lib/doc.lib.php';
+require_once DOL_DOCUMENT_ROOT.'/core/lib/signature.lib.php';
 
 
 /**