diff --git a/etc/inc/services.inc b/etc/inc/services.inc
index 4d67445c1e..1902bbbd5a 100644
--- a/etc/inc/services.inc
+++ b/etc/inc/services.inc
@@ -1188,7 +1188,7 @@ $dnscfgv6
 EOD;
 
 		if (is_ipaddrv6($dhcpv6ifconf['prefixrange']['from']) && is_ipaddrv6($dhcpv6ifconf['prefixrange']['to'])) {
-			$dhcpdv6conf .= "	prefix6 {$dhcpv6ifconf['prefixrange']['from']} {$dhcpv6ifconf['prefixrange']['to']}/{$dhcpv6ifconf['prefixrange']['prefixlength']};\n";
+			$dhcpdv6conf .= "	prefix6 {$dhcpv6ifconf['prefixrange']['from']} {$dhcpv6ifconf['prefixrange']['to']} /{$dhcpv6ifconf['prefixrange']['prefixlength']};\n";
 		}
 		if (is_ipaddrv6($dhcpv6ifconf['dns6ip'])) {
 			$dhcpdv6conf .= "       option dhcp6.name-servers {$dhcpv6ifconf['dns6ip']};\n";