diff --git a/krebs/4lib/types.nix b/krebs/4lib/types.nix
index 112984445..32d1daf9d 100644
--- a/krebs/4lib/types.nix
+++ b/krebs/4lib/types.nix
@@ -111,7 +111,7 @@ types // rec {
               );
             };
             pubkey = mkOption {
-              type = str;
+              type = tinc-pubkey;
             };
           };
         }));
@@ -214,6 +214,8 @@ types // rec {
     };
   };
 
+  tinc-pubkey = str;
+
   krebs.file-location = types.submodule {
     options = {
       # TODO user