Index: tests/meta/dumpable.cfa
===================================================================
--- tests/meta/dumpable.cfa	(revision 470618c0eaa607fe44af9046522d8de883087e5f)
+++ tests/meta/dumpable.cfa	(revision f0567a837a4f142b940e35e5251b8a7e2f6e6fe1)
@@ -72,6 +72,8 @@
 	}
 
-	if((buf.f_bsize * buf.f_bavail) < 536870912) {
-		serr | "Available diskspace is less than ~500Mb: " | (buf.f_bsize * buf.f_bavail);
+	uint64_t avail = buf.f_bavail;
+	avail *= buf.f_bsize;
+	if(avail < 536870912_l64u) {
+		serr | "Available diskspace is less than ~500Mb: " | avail;
 	}