diff --git a/drivers/net/can/peak_canfd/peak_pciefd_main.c b/drivers/net/can/peak_canfd/peak_pciefd_main.c
index b4efd711f824ccd1c832af8817e09bf2e00b2b5c..788c3464a3b0e95aaa101591750b9de493a34a18 100644
--- a/drivers/net/can/peak_canfd/peak_pciefd_main.c
+++ b/drivers/net/can/peak_canfd/peak_pciefd_main.c
@@ -825,7 +825,10 @@ static int peak_pciefd_probe(struct pci_dev *pdev,
 err_disable_pci:
 	pci_disable_device(pdev);
 
-	return err;
+	/* pci_xxx_config_word() return positive PCIBIOS_xxx error codes while
+	 * the probe() function must return a negative errno in case of failure
+	 * (err is unchanged if negative) */
+	return pcibios_err_to_errno(err);
 }
 
 /* free the board structure object, as well as its resources: */
diff --git a/drivers/net/can/sja1000/peak_pci.c b/drivers/net/can/sja1000/peak_pci.c
index 131026fbc2d77cbc3ccb5903daa10f8920f8ae17..5adc95c922eef2d9f968a2dea3bac7c2dd3bfda2 100644
--- a/drivers/net/can/sja1000/peak_pci.c
+++ b/drivers/net/can/sja1000/peak_pci.c
@@ -717,7 +717,10 @@ static int peak_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 failure_disable_pci:
 	pci_disable_device(pdev);
 
-	return err;
+	/* pci_xxx_config_word() return positive PCIBIOS_xxx error codes while
+	 * the probe() function must return a negative errno in case of failure
+	 * (err is unchanged if negative) */
+	return pcibios_err_to_errno(err);
 }
 
 static void peak_pci_remove(struct pci_dev *pdev)