diff --git a/arch/posix/include/kernel_arch_thread.h b/arch/posix/include/kernel_arch_thread.h
index d0f2d6e55ef..d2dd95742e9 100644
--- a/arch/posix/include/kernel_arch_thread.h
+++ b/arch/posix/include/kernel_arch_thread.h
@@ -41,6 +41,7 @@ struct _callee_saved {
 
 struct _thread_arch {
 	/* nothing for now */
+	int dummy;
 };
 
 typedef struct _thread_arch _thread_arch_t;