diff --git a/arch/x86_64/src/common/x86_64_pci.c b/arch/x86_64/src/common/x86_64_pci.c
index e9d683ecd1b..b6e357b83db 100644
--- a/arch/x86_64/src/common/x86_64_pci.c
+++ b/arch/x86_64/src/common/x86_64_pci.c
@@ -60,9 +60,9 @@
  * Private Functions Definitions
  ****************************************************************************/
 
-static int x86_64_pci_write(struct pci_bus_s *bus, unsigned int devfn,
+static int x86_64_pci_write(struct pci_bus_s *bus, uint32_t devfn,
                             int where, int size, uint32_t val);
-static int x86_64_pci_read(struct pci_bus_s *bus, unsigned int devfn,
+static int x86_64_pci_read(struct pci_bus_s *bus, uint32_t devfn,
                            int where, int size, uint32_t *val);
 static uintptr_t x86_64_pci_map(struct pci_bus_s *bus, uintptr_t start,
                                 uintptr_t end);
@@ -127,7 +127,7 @@ static struct pci_controller_s g_x86_64_pci =
  *
  ****************************************************************************/
 
-static int x86_64_pci_write(struct pci_bus_s *bus, unsigned int devfn,
+static int x86_64_pci_write(struct pci_bus_s *bus, uint32_t devfn,
                             int where, int size, uint32_t val)
 {
   uint8_t offset_mask = (4 - size);
@@ -173,7 +173,7 @@ static int x86_64_pci_write(struct pci_bus_s *bus, unsigned int devfn,
  *
  ****************************************************************************/
 
-static int x86_64_pci_read(struct pci_bus_s *bus, unsigned int devfn,
+static int x86_64_pci_read(struct pci_bus_s *bus, uint32_t devfn,
                            int where, int size, uint32_t *val)
 {
   uint8_t offset_mask = 4 - size;
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index c5d9d05a09f..7752c1bd466 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -758,7 +758,8 @@ static void pci_setup_device(FAR struct pci_device_s *dev, int max_bar,
       pci_write_config_dword(dev, base_address_0, res->start);
       if (mask & PCI_BASE_ADDRESS_MEM_TYPE_64)
         {
-          pci_write_config_dword(dev, base_address_1, res->start >> 32);
+          pci_write_config_dword(dev, base_address_1,
+                                 (uint64_t)res->start >> 32);
         }
 
       start = res->start;
@@ -865,7 +866,7 @@ static void pci_presetup_bridge(FAR struct pci_device_s *dev)
       pci_write_config_word(dev, PCI_PREF_MEMORY_BASE,
                             (ctrl->mem_pref.start & 0xfff00000) >> 16);
       pci_write_config_dword(dev, PCI_PREF_BASE_UPPER32,
-                             ctrl->mem_pref.start >> 32);
+                             (uint64_t)ctrl->mem_pref.start >> 32);
       cmdstat |= PCI_COMMAND_MEMORY;
     }
   else
@@ -929,7 +930,7 @@ static void pci_postsetup_bridge(FAR struct pci_device_s *dev)
       pci_write_config_word(dev, PCI_PREF_MEMORY_LIMIT,
                             ((ctrl->mem_pref.start - 1) & 0xfff00000) >> 16);
       pci_write_config_dword(dev, PCI_PREF_LIMIT_UPPER32,
-                             (ctrl->mem_pref.start - 1) >> 32);
+                             (uint64_t)(ctrl->mem_pref.start - 1) >> 32);
     }
 
   if (pci_resource_size(&ctrl->io))
diff --git a/include/nuttx/pci/pci.h b/include/nuttx/pci/pci.h
index 08905f6540e..f1f19442880 100644
--- a/include/nuttx/pci/pci.h
+++ b/include/nuttx/pci/pci.h
@@ -313,9 +313,9 @@ struct pci_bus_s
 
 struct pci_ops_s
 {
-  CODE int (*read)(FAR struct pci_bus_s *bus, unsigned int devfn, int where,
+  CODE int (*read)(FAR struct pci_bus_s *bus, uint32_t devfn, int where,
                    int size, FAR uint32_t *val);
-  CODE int (*write)(FAR struct pci_bus_s *bus, unsigned int devfn, int where,
+  CODE int (*write)(FAR struct pci_bus_s *bus, uint32_t devfn, int where,
                     int size, uint32_t val);
 
   /* Return memory address for pci resource */