diff --git a/lib/Tools/go b/lib/Tools/go
--- a/lib/Tools/go
+++ b/lib/Tools/go
@@ -1,13 +1,13 @@
 #!/usr/bin/env bash
 #
 # Author: Makarius
 #
 # DESCRIPTION: invoke go within the Isabelle environment
 
 if [ -z "$ISABELLE_GOEXE" ]; then
   echo "Missing Go installation: need to run \"isabelle go_setup\" first" >&2
   exit 2
 else
-  export GOROOT="$ISABELLE_GOROOT"
+  export GOROOT="$(platform_path "$ISABELLE_GOROOT")"
   exec "$ISABELLE_GOEXE/go" "$@"
 fi
diff --git a/lib/Tools/gofmt b/lib/Tools/gofmt
--- a/lib/Tools/gofmt
+++ b/lib/Tools/gofmt
@@ -1,13 +1,13 @@
 #!/usr/bin/env bash
 #
 # Author: Makarius
 #
 # DESCRIPTION: invoke gofmt within the Isabelle environment
 
 if [ -z "$ISABELLE_GOEXE" ]; then
   echo "Missing Go installation: need to run \"isabelle go_setup\" first" >&2
   exit 2
 else
-  export GOROOT="$ISABELLE_GOROOT"
+  export GOROOT="$(platform_path "$ISABELLE_GOROOT")"
   exec "$ISABELLE_GOEXE/gofmt" "$@"
 fi