diff --git a/modules/lnd.nix b/modules/lnd.nix
index e4b591a..fcadc5c 100644
--- a/modules/lnd.nix
+++ b/modules/lnd.nix
@@ -157,6 +157,16 @@ in {
       { assertion = bitcoind.prune == 0;
         message = "lnd does not support bitcoind pruning.";
       }
+      { assertion =
+          !(config.services ? clightning)
+          || !config.services.clightning.enable
+          || config.services.clightning.port != cfg.port;
+        message = ''
+          LND and clightning can't both bind to lightning port 9735. Either
+          disable LND/clightning or change services.clightning.port or
+          services.lnd.port to a port other than 9735.
+        '';
+      }
     ];
 
     services.bitcoind = {
diff --git a/modules/nix-bitcoin.nix b/modules/nix-bitcoin.nix
index fc8696b..48cb7c4 100644
--- a/modules/nix-bitcoin.nix
+++ b/modules/nix-bitcoin.nix
@@ -41,16 +41,4 @@ with lib;
       };
     };
   };
-
-  config = {
-    assertions = [
-      { assertion = (config.services.lnd.enable -> ( !config.services.clightning.enable || config.services.clightning.port != config.services.lnd.port));
-        message = ''
-          LND and clightning can't both bind to lightning port 9735. Either
-          disable LND/clightning or change services.clightning.bindPort or
-          services.lnd.port to a port other than 9735.
-        '';
-      }
-    ];
-  };
 }