diff --git a/tests/run-pass/pthreads.rs b/tests/run-pass-fullmir/threads.rs
similarity index 80%
rename from tests/run-pass/pthreads.rs
rename to tests/run-pass-fullmir/threads.rs
index ec7e082a5d5f..93a08bfc2588 100644
--- a/tests/run-pass/pthreads.rs
+++ b/tests/run-pass-fullmir/threads.rs
@@ -1,4 +1,5 @@
-// Just instantiate some data structures to make sure we got all their foreign items covered
+// Just instantiate some data structures to make sure we got all their foreign items covered.
+// Requires full MIR on Windows.
 
 use std::sync;