diff --git a/nixos/modules/tasks/network-interfaces.nix b/nixos/modules/tasks/network-interfaces.nix
index 29e439860efa..e4b200ed534c 100644
--- a/nixos/modules/tasks/network-interfaces.nix
+++ b/nixos/modules/tasks/network-interfaces.nix
@@ -14,7 +14,7 @@ let
   slaves = concatMap (i: i.interfaces) (attrValues cfg.bonds)
     ++ concatMap (i: i.interfaces) (attrValues cfg.bridges);
 
-  slaveIfs = map (i: cfg.interfaces.${i}) (filter (i: cfg.interfaces ? i) slaves);
+  slaveIfs = map (i: cfg.interfaces.${i}) (filter (i: cfg.interfaces ? ${i}) slaves);
 
   # We must escape interfaces due to the systemd interpretation
   subsystemDevice = interface: