diff --git a/htdocs/core/modules/propale/doc/pdf_azur.modules.php b/htdocs/core/modules/propale/doc/pdf_azur.modules.php
index eac6e0261ee..5f637373507 100644
--- a/htdocs/core/modules/propale/doc/pdf_azur.modules.php
+++ b/htdocs/core/modules/propale/doc/pdf_azur.modules.php
@@ -675,10 +675,18 @@ class pdf_azur extends ModelePDFPropales
 
 					// retrieve global local tax
 					if ($localtax1_type && $localtax1ligne != 0) {
-						$this->localtax1[$localtax1_type][$localtax1_rate] += $localtax1ligne;
+						if (empty($this->localtax1[$localtax1_type][$localtax1_rate])) {
+							$this->localtax1[$localtax1_type][$localtax1_rate] = $localtax1ligne;
+						} else {
+							$this->localtax1[$localtax1_type][$localtax1_rate] += $localtax1ligne;
+						}
 					}
 					if ($localtax2_type && $localtax2ligne != 0) {
-						$this->localtax2[$localtax2_type][$localtax2_rate] += $localtax2ligne;
+						if (empty($this->localtax2[$localtax2_type][$localtax2_rate])) {
+							$this->localtax2[$localtax2_type][$localtax2_rate] = $localtax2ligne;
+						} else {
+							$this->localtax2[$localtax2_type][$localtax2_rate] += $localtax2ligne;
+						}
 					}
 
 					if (($object->lines[$i]->info_bits & 0x01) == 0x01) {