diff --git a/src/device/resource_allocator_v4.c b/src/device/resource_allocator_v4.c
index 6e4aa5e..511c450 100644
--- a/src/device/resource_allocator_v4.c
+++ b/src/device/resource_allocator_v4.c
@@ -222,7 +222,7 @@
 	else if (res->flags & IORESOURCE_IO)
 		return 0;   /* No special alignment required --> log2(1) */
 
-	die("Unexpected resource type: flags(%d)!\n", res->flags);
+	die("Unexpected resource type: flags(%lu)!\n", res->flags);
 }
 
 /*