diff --git a/tests/mkcert.gmk b/tests/mkcert.gmk
index 34962fa4ea6..0e158c95f6d 100644
--- a/tests/mkcert.gmk
+++ b/tests/mkcert.gmk
@@ -1,5 +1,5 @@
 server  = $(shell hostname)
-domain  = $(shell domainname)
+domain  = $(shell dnsdomainname)
 name    = $(server)
 
 country = SE