diff --git a/hw/pci/pci_bridge.c b/hw/pci/pci_bridge.c
index b2e50c36a0..40a39f57cb 100644
--- a/hw/pci/pci_bridge.c
+++ b/hw/pci/pci_bridge.c
@@ -412,22 +412,36 @@ void pci_bridge_map_irq(PCIBridge *br, const char* bus_name,
 
 int pci_bridge_qemu_reserve_cap_init(PCIDevice *dev, int cap_offset,
                                      uint32_t bus_reserve, uint64_t io_reserve,
-                                     uint32_t mem_non_pref_reserve,
-                                     uint32_t mem_pref_32_reserve,
+                                     uint64_t mem_non_pref_reserve,
+                                     uint64_t mem_pref_32_reserve,
                                      uint64_t mem_pref_64_reserve,
                                      Error **errp)
 {
-    if (mem_pref_32_reserve != (uint32_t)-1 &&
+    if (mem_pref_32_reserve != (uint64_t)-1 &&
         mem_pref_64_reserve != (uint64_t)-1) {
         error_setg(errp,
                    "PCI resource reserve cap: PREF32 and PREF64 conflict");
         return -EINVAL;
     }
 
+    if (mem_non_pref_reserve != (uint64_t)-1 &&
+        mem_non_pref_reserve >= (1ULL << 32)) {
+        error_setg(errp,
+                   "PCI resource reserve cap: mem-reserve must be less than 4G");
+        return -EINVAL;
+    }
+
+    if (mem_pref_32_reserve != (uint64_t)-1 &&
+        mem_pref_32_reserve >= (1ULL << 32)) {
+        error_setg(errp,
+                   "PCI resource reserve cap: pref32-reserve  must be less than 4G");
+        return -EINVAL;
+    }
+
     if (bus_reserve == (uint32_t)-1 &&
         io_reserve == (uint64_t)-1 &&
-        mem_non_pref_reserve == (uint32_t)-1 &&
-        mem_pref_32_reserve == (uint32_t)-1 &&
+        mem_non_pref_reserve == (uint64_t)-1 &&
+        mem_pref_32_reserve == (uint64_t)-1 &&
         mem_pref_64_reserve == (uint64_t)-1) {
         return 0;
     }
diff --git a/include/hw/pci/pci_bridge.h b/include/hw/pci/pci_bridge.h
index 9b44ffd22a..0347da52d2 100644
--- a/include/hw/pci/pci_bridge.h
+++ b/include/hw/pci/pci_bridge.h
@@ -135,8 +135,8 @@ typedef struct PCIBridgeQemuCap {
 
 int pci_bridge_qemu_reserve_cap_init(PCIDevice *dev, int cap_offset,
                               uint32_t bus_reserve, uint64_t io_reserve,
-                              uint32_t mem_non_pref_reserve,
-                              uint32_t mem_pref_32_reserve,
+                              uint64_t mem_non_pref_reserve,
+                              uint64_t mem_pref_32_reserve,
                               uint64_t mem_pref_64_reserve,
                               Error **errp);