diff --git a/pkgs/build-support/dotnet/build-dotnet-module/hook/default.nix b/pkgs/build-support/dotnet/build-dotnet-module/hook/default.nix
index e1f7cd816719..58a89b855e70 100644
--- a/pkgs/build-support/dotnet/build-dotnet-module/hook/default.nix
+++ b/pkgs/build-support/dotnet/build-dotnet-module/hook/default.nix
@@ -9,7 +9,7 @@
 makeSetupHook {
   name = "dotnet-hook";
   substitutions = {
-    dotnetRuntime = dotnet-runtime;
+    dotnetRuntime = lib.defaultTo "" dotnet-runtime;
     wrapperPath = lib.makeBinPath [
       which
       coreutils