diff --git a/src/libsyntax_ext/global_allocator.rs b/src/libsyntax_ext/global_allocator.rs
index 71c9e6cd23d44..33072487e19f4 100644
--- a/src/libsyntax_ext/global_allocator.rs
+++ b/src/libsyntax_ext/global_allocator.rs
@@ -30,7 +30,7 @@ pub fn expand(
     };
 
     // Generate a bunch of new items using the AllocFnFactory
-    let span = item.span.with_ctxt(SyntaxContext::empty().apply_mark(ecx.current_expansion.mark));
+    let span = item.span.with_ctxt(SyntaxContext::empty().apply_mark(ecx.current_expansion.id));
     let f = AllocFnFactory {
         span,
         kind: AllocatorKind::Global,