diff --git a/ogp_spi.c b/ogp_spi.c
index 23431d1..a624dfd 100644
--- a/ogp_spi.c
+++ b/ogp_spi.c
@@ -132,7 +132,7 @@
 	if (!dev)
 		return 1;
 
-	io_base_addr = pcidev_readbar(dev, PCI_BASE_ADDRESS_0);
+	uint32_t io_base_addr = pcidev_readbar(dev, PCI_BASE_ADDRESS_0);
 	if (!io_base_addr)
 		return 1;