diff --git a/src/thread.c b/src/thread.c
index c03cdda0fae..6f12d796ff9 100644
--- a/src/thread.c
+++ b/src/thread.c
@@ -26,7 +26,7 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 #include "coding.h"
 #include "syssignal.h"
 
-static struct thread_state main_thread;
+static struct thread_state alignas (GCALIGNMENT) main_thread;
 
 struct thread_state *current_thread = &main_thread;