diff --git a/roles/dhcpcd/templates/dhcpcd.conf.j2 b/roles/dhcpcd/templates/dhcpcd.conf.j2
index c31497b..d3e2ec3 100644
--- a/roles/dhcpcd/templates/dhcpcd.conf.j2
+++ b/roles/dhcpcd/templates/dhcpcd.conf.j2
@@ -14,11 +14,11 @@ controlgroup {{ dhcpcd_controlgroup }}
 {% endif %}
 {% if dhcpcd_allow_interfaces is defined %}
 
-allowinterfaces {{ dhcpcd_allow_interfaces }}
+allowinterfaces {{ dhcpcd_allow_interfaces|join(' ')}}
 {% endif %}
 {% if dhcpcd_deny_interfaces is defined %}
 
-denyinterfaces {{ dhcpcd_deny_interfaces }}
+denyinterfaces {{ dhcpcd_deny_interfaces|join(' ') }}
 {% endif %}
 
 # Inform the DHCP server of our hostname for DDNS.