diff --git a/pkgs/applications/networking/syncthing012/default.nix b/pkgs/applications/networking/syncthing012/default.nix
index 5735dd68bcd2..4b5359555f4a 100644
--- a/pkgs/applications/networking/syncthing012/default.nix
+++ b/pkgs/applications/networking/syncthing012/default.nix
@@ -5,8 +5,6 @@ buildGoPackage rec {
   version = "0.12.15";
   rev = "v${version}";
 
-  buildFlags = "--tags noupgrade,release";
-  
   goPackagePath = "github.com/syncthing/syncthing";
 
   src = fetchFromGitHub {
@@ -22,4 +20,8 @@ buildGoPackage rec {
     # Mostly a cosmetic change
     sed -i 's,unknown-dev,${version},g' cmd/syncthing/main.go
   '';
+
+  preBuild = ''
+    export buildFlagsArray+=("-tags" "noupgrade release")
+  '';
 }