diff --git a/nixos/modules/services/home-automation/home-assistant.nix b/nixos/modules/services/home-automation/home-assistant.nix
index f389b2d84dab..0a399e0774d1 100644
--- a/nixos/modules/services/home-automation/home-assistant.nix
+++ b/nixos/modules/services/home-automation/home-assistant.nix
@@ -75,7 +75,7 @@ let
   # Create parts of the lovelace config that reference lovelave modules as resources
   customLovelaceModulesResources = {
     lovelace.resources = map (card: {
-      url = "/local/nixos-lovelace-modules/${card.entrypoint or card.pname}.js?${card.version}";
+      url = "/local/nixos-lovelace-modules/${card.entrypoint or card.pname + ".js"}?${card.version}";
       type = "module";
     }) cfg.customLovelaceModules;
   };
diff --git a/pkgs/servers/home-assistant/custom-lovelace-modules/light-entity-card/default.nix b/pkgs/servers/home-assistant/custom-lovelace-modules/light-entity-card/default.nix
index 0cdf9ee1677e..9c1e97b0f8ed 100644
--- a/pkgs/servers/home-assistant/custom-lovelace-modules/light-entity-card/default.nix
+++ b/pkgs/servers/home-assistant/custom-lovelace-modules/light-entity-card/default.nix
@@ -27,7 +27,7 @@ buildNpmPackage rec {
     runHook postInstall
   '';
 
-  passthru.entrypoint = "light-entity-card";
+  passthru.entrypoint = "light-entity-card.js";
 
   meta = with lib; {
     description = "Control any light or switch entity";