diff --git a/htdocs/core/modules/supplier_order/doc/pdf_cornas.modules.php b/htdocs/core/modules/supplier_order/doc/pdf_cornas.modules.php
index 3b12747c924..1a4fb9c8754 100644
--- a/htdocs/core/modules/supplier_order/doc/pdf_cornas.modules.php
+++ b/htdocs/core/modules/supplier_order/doc/pdf_cornas.modules.php
@@ -335,7 +335,7 @@ class pdf_cornas extends ModelePDFSuppliersOrders
 				$pdf->SetCreator("Dolibarr ".DOL_VERSION);
 				$pdf->SetAuthor($outputlangs->convToOutputCharset($user->getFullName($outputlangs)));
 				$pdf->SetKeyWords($outputlangs->convToOutputCharset($object->ref)." ".$outputlangs->transnoentities("Order")." ".$outputlangs->convToOutputCharset($object->thirdparty->name));
-				if (!empty($conf->global->MAIN_DISABLE_PDF_COMPRESSION)) {
+				if (getDolGlobalString('MAIN_DISABLE_PDF_COMPRESSION')) {
 					$pdf->SetCompression(false);
 				}
 
diff --git a/htdocs/core/modules/supplier_order/doc/pdf_muscadet.modules.php b/htdocs/core/modules/supplier_order/doc/pdf_muscadet.modules.php
index 2ba9ae7f1ae..bf0bff7fb6a 100644
--- a/htdocs/core/modules/supplier_order/doc/pdf_muscadet.modules.php
+++ b/htdocs/core/modules/supplier_order/doc/pdf_muscadet.modules.php
@@ -350,7 +350,7 @@ class pdf_muscadet extends ModelePDFSuppliersOrders
 				$pdf->SetAuthor($outputlangs->convToOutputCharset($user->getFullName($outputlangs)));
 
 				$pdf->SetKeyWords($outputlangs->convToOutputCharset($object->ref)." ".$outputlangs->transnoentities("PurchaseOrder")." ".$outputlangs->convToOutputCharset($object->thirdparty->name));
-				if (!empty($conf->global->MAIN_DISABLE_PDF_COMPRESSION)) {
+				if (getDolGlobalString('MAIN_DISABLE_PDF_COMPRESSION')) {
 					$pdf->SetCompression(false);
 				}
 
diff --git a/htdocs/core/modules/supplier_payment/doc/pdf_standard.modules.php b/htdocs/core/modules/supplier_payment/doc/pdf_standard.modules.php
index 8b131c4e0f2..24b352a3ff8 100644
--- a/htdocs/core/modules/supplier_payment/doc/pdf_standard.modules.php
+++ b/htdocs/core/modules/supplier_payment/doc/pdf_standard.modules.php
@@ -272,7 +272,7 @@ class pdf_standard extends ModelePDFSuppliersPayments
 				$pdf->SetCreator("Dolibarr ".DOL_VERSION);
 				$pdf->SetAuthor($outputlangs->convToOutputCharset($user->getFullName($outputlangs)));
 				$pdf->SetKeyWords($outputlangs->convToOutputCharset($object->ref)." ".$outputlangs->transnoentities("Order")." ".$outputlangs->convToOutputCharset($object->thirdparty->name));
-				if (!empty($conf->global->MAIN_DISABLE_PDF_COMPRESSION)) {
+				if (getDolGlobalString('MAIN_DISABLE_PDF_COMPRESSION')) {
 					$pdf->SetCompression(false);
 				}