diff --git a/api.go b/api.go
index f546c61..f108f50 100644
--- a/api.go
+++ b/api.go
@@ -168,6 +168,15 @@ func apiPutDomain(c echo.Context) error {
 		}
 	}
 
+	if len(certgroups) == 0 { //certgroups is empty, so start fresh
+		var cg CertGroup
+		cg.PrimaryDomain = appconf.PrimaryDomain
+		if domain != appconf.PrimaryDomain {
+			cg.Domains = append(cg.Domains, domain)
+		}
+		certgroups = append(certgroups, cg)
+	}
+
 	//write list to disk
 	err := writeDomains()
 	if err != nil {