diff --git a/build/toolbase/gotoolchain/def.bzl b/build/toolbase/gotoolchain/def.bzl
index 5c421e6..2ff5fe0 100644
--- a/build/toolbase/gotoolchain/def.bzl
+++ b/build/toolbase/gotoolchain/def.bzl
@@ -17,7 +17,7 @@
         template = ctx.file._template,
         output = out,
         substitutions = {
-            "GOROOT": go.root,
+            "GOROOT": go.sdk.root_file.dirname,
             "GOTOOL": go.go.path,
         },
     )