diff --git a/pci.c b/pci.c
index 81e9cec..eb0bb36 100644
--- a/pci.c
+++ b/pci.c
@@ -119,6 +119,9 @@
 {
 	union pci_config_address pci_config_address;
 
+	if (size > 4)
+		size = 4;
+
 	pci_config_address.w = ioport__read32(&pci_config_address_bits);
 	/*
 	 * If someone accesses PCI configuration space offsets that are not
@@ -135,6 +138,9 @@
 {
 	union pci_config_address pci_config_address;
 
+	if (size > 4)
+		size = 4;
+
 	pci_config_address.w = ioport__read32(&pci_config_address_bits);
 	/*
 	 * If someone accesses PCI configuration space offsets that are not
@@ -248,6 +254,9 @@
 	cfg_addr.w		= (u32)addr;
 	cfg_addr.enable_bit	= 1;
 
+	if (len > 4)
+		len = 4;
+
 	if (is_write)
 		pci__config_wr(kvm, cfg_addr, data, len);
 	else