diff --git a/mcfgthread/gthr_aux.h b/mcfgthread/gthr_aux.h
index 3db3a11449..1818e6089e 100644
--- a/mcfgthread/gthr_aux.h
+++ b/mcfgthread/gthr_aux.h
@@ -68,8 +68,7 @@ __MCF_gthr_call_once_seh_take_over(_MCF_once* __once, __MCF_cxa_dtor_any_ __init
 /* This is a type-generic macro. `__init_proc` may be of any calling convention,
  * and may take an arbitrary pointer.  */
 #define __MCF_GTHR_CALL_ONCE_SEH(__once, __init_proc, __arg)  \
-    __MCF_gthr_call_once_seh(__once,  \
-       __MCF_CAST_PTR(__MCF_cxa_dtor_cdecl, __init_proc), __arg)
+    __MCF_gthr_call_once_seh(__once, __MCF_CAST_PTR(__MCF_cxa_dtor_cdecl, __init_proc), __arg)
 
 /* This is an auxiliary function for converting a `__MCF_timespec` to the
  * number of milliseconds since the Unix epoch, with boundary checking.  */