diff --git a/conn.go b/conn.go
index 1a1f09a1..62234656 100644
--- a/conn.go
+++ b/conn.go
@@ -221,6 +221,10 @@ func DialOpen(d Dialer, name string) (_ driver.Conn, err error) {
 
 func dial(d Dialer, o values) (net.Conn, error) {
 	ntw, addr := network(o)
+	// SSL is not necessary or supported over UNIX domain sockets
+	if ntw == "unix" {
+		o["sslmode"] = "disable"
+	}
 
 	// Zero or not specified means wait indefinitely.
 	if timeout := o.Get("connect_timeout"); timeout != "" && timeout != "0" {