diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
index 435a6cfd57..4aca0c5912 100644
--- a/hw/pci/pcie.c
+++ b/hw/pci/pcie.c
@@ -608,7 +608,7 @@ void pcie_add_capability(PCIDevice *dev,
 
     assert(offset >= PCI_CONFIG_SPACE_SIZE);
     assert(offset < offset + size);
-    assert(offset + size < PCIE_CONFIG_SPACE_SIZE);
+    assert(offset + size <= PCIE_CONFIG_SPACE_SIZE);
     assert(size >= 8);
     assert(pci_is_express(dev));