diff --git a/htdocs/core/modules/commande/doc/pdf_edison.modules.php b/htdocs/core/modules/commande/doc/pdf_edison.modules.php
index 438fe3307e3..9f80359e54e 100644
--- a/htdocs/core/modules/commande/doc/pdf_edison.modules.php
+++ b/htdocs/core/modules/commande/doc/pdf_edison.modules.php
@@ -298,7 +298,7 @@ class pdf_edison extends ModelePDFCommandes
 				$pdf->Output($file,'F');
 
 				// Actions on extra fields (by external module or standard code)
-				if (is_object($hookmanager))
+				if (! is_object($hookmanager))
 				{
 					include_once(DOL_DOCUMENT_ROOT.'/core/class/hookmanager.class.php');
 					$hookmanager=new HookManager($this->db);
diff --git a/htdocs/core/modules/commande/doc/pdf_einstein.modules.php b/htdocs/core/modules/commande/doc/pdf_einstein.modules.php
index 4ba7bd8ca31..9c934dfc2f9 100644
--- a/htdocs/core/modules/commande/doc/pdf_einstein.modules.php
+++ b/htdocs/core/modules/commande/doc/pdf_einstein.modules.php
@@ -407,7 +407,7 @@ class pdf_einstein extends ModelePDFCommandes
 				$pdf->Output($file,'F');
 
 				// Actions on extra fields (by external module or standard code)
-				if (is_object($hookmanager))
+				if (! is_object($hookmanager))
 				{
 					include_once(DOL_DOCUMENT_ROOT.'/core/class/hookmanager.class.php');
 					$hookmanager=new HookManager($this->db);
diff --git a/htdocs/core/modules/facture/doc/pdf_crabe.modules.php b/htdocs/core/modules/facture/doc/pdf_crabe.modules.php
index 14a450e8491..fc16f446890 100755
--- a/htdocs/core/modules/facture/doc/pdf_crabe.modules.php
+++ b/htdocs/core/modules/facture/doc/pdf_crabe.modules.php
@@ -412,7 +412,7 @@ class pdf_crabe extends ModelePDFFactures
 				$pdf->Output($file,'F');
 
 				// Add pdfgeneration hook
-				if (is_object($hookmanager))
+				if (! is_object($hookmanager))
 				{
 					include_once(DOL_DOCUMENT_ROOT.'/core/class/hookmanager.class.php');
 					$hookmanager=new HookManager($this->db);
diff --git a/htdocs/core/modules/facture/doc/pdf_oursin.modules.php b/htdocs/core/modules/facture/doc/pdf_oursin.modules.php
index 07efe8f3a62..267607e8aa2 100755
--- a/htdocs/core/modules/facture/doc/pdf_oursin.modules.php
+++ b/htdocs/core/modules/facture/doc/pdf_oursin.modules.php
@@ -300,7 +300,7 @@ class pdf_oursin extends ModelePDFFactures
 				$pdf->Output($file,'F');
 
 				// Actions on extra fields (by external module or standard code)
-				if (is_object($hookmanager))
+				if (! is_object($hookmanager))
 				{
 					include_once(DOL_DOCUMENT_ROOT.'/core/class/hookmanager.class.php');
 					$hookmanager=new HookManager($this->db);
diff --git a/htdocs/core/modules/propale/doc/pdf_azur.modules.php b/htdocs/core/modules/propale/doc/pdf_azur.modules.php
index 0208eec114f..5e6c84bda97 100644
--- a/htdocs/core/modules/propale/doc/pdf_azur.modules.php
+++ b/htdocs/core/modules/propale/doc/pdf_azur.modules.php
@@ -393,7 +393,7 @@ class pdf_azur extends ModelePDFPropales
 				$pdf->Output($file,'F');
 
 				// Actions on extra fields (by external module or standard code)
-				if (is_object($hookmanager))
+				if (! is_object($hookmanager))
 				{
 					include_once(DOL_DOCUMENT_ROOT.'/core/class/hookmanager.class.php');
 					$hookmanager=new HookManager($this->db);
diff --git a/htdocs/core/modules/propale/doc/pdf_jaune.modules.php b/htdocs/core/modules/propale/doc/pdf_jaune.modules.php
index 74df21eb178..6f916f4a470 100644
--- a/htdocs/core/modules/propale/doc/pdf_jaune.modules.php
+++ b/htdocs/core/modules/propale/doc/pdf_jaune.modules.php
@@ -393,7 +393,7 @@ class pdf_jaune extends ModelePDFPropales
 				$pdf->Output($file,'F');
 
 				// Actions on extra fields (by external module or standard code)
-				if (is_object($hookmanager))
+				if (! is_object($hookmanager))
 				{
 					include_once(DOL_DOCUMENT_ROOT.'/core/class/hookmanager.class.php');
 					$hookmanager=new HookManager($this->db);
diff --git a/htdocs/core/modules/supplier_invoice/pdf/pdf_canelle.modules.php b/htdocs/core/modules/supplier_invoice/pdf/pdf_canelle.modules.php
index ee9599cfeaf..46f3bb96904 100755
--- a/htdocs/core/modules/supplier_invoice/pdf/pdf_canelle.modules.php
+++ b/htdocs/core/modules/supplier_invoice/pdf/pdf_canelle.modules.php
@@ -398,7 +398,7 @@ class pdf_canelle extends ModelePDFSuppliersInvoices
 				$pdf->Output($file,'F');
 
 				// Actions on extra fields (by external module or standard code)
-				if (is_object($hookmanager))
+				if (! is_object($hookmanager))
 				{
 					include_once(DOL_DOCUMENT_ROOT.'/core/class/hookmanager.class.php');
 					$hookmanager=new HookManager($this->db);
diff --git a/htdocs/core/modules/supplier_order/pdf/pdf_muscadet.modules.php b/htdocs/core/modules/supplier_order/pdf/pdf_muscadet.modules.php
index 5cd9ae7ad70..36632cde0bf 100644
--- a/htdocs/core/modules/supplier_order/pdf/pdf_muscadet.modules.php
+++ b/htdocs/core/modules/supplier_order/pdf/pdf_muscadet.modules.php
@@ -406,7 +406,7 @@ class pdf_muscadet extends ModelePDFSuppliersOrders
 
 
 				// Add pdfgeneration hook
-				if (is_object($hookmanager))
+				if (! is_object($hookmanager))
 				{
 					include_once(DOL_DOCUMENT_ROOT.'/core/class/hookmanager.class.php');
 					$hookmanager=new HookManager($this->db);