diff --git a/pkgs/by-name/fm/fmd-server/package.nix b/pkgs/by-name/fm/fmd-server/package.nix
index e5fad6c9ac32..5ed9b08dc0ab 100644
--- a/pkgs/by-name/fm/fmd-server/package.nix
+++ b/pkgs/by-name/fm/fmd-server/package.nix
@@ -35,6 +35,10 @@ buildGoModule (
 
     vendorHash = "sha256-cFIg9mOSQbrYHW4kg4aTeTaF+gy1jNpAlg8qepb81Jc=";
 
+    preBuild = ''
+      cp -r ${ui}/${ui.distRoot} web/
+    '';
+
     nativeInstallCheckInputs = [ versionCheckHook ];
     versionCheckProgramArg = "version";
 
@@ -74,10 +78,6 @@ buildGoModule (
       '';
     };
 
-    postUnpack = ''
-      cp -r ${ui}/${ui.distRoot} /build/source/web/
-    '';
-
     meta = {
       description = "Server to communicate with the FindMyDevice app and save the latest (encrypted) location";
       homepage = "https://fmd-foss.org/";