diff --git a/sys/pc98/i386/machdep.c b/sys/pc98/i386/machdep.c
index caa579c664cd..08cd9c80dfdd 100644
--- a/sys/pc98/i386/machdep.c
+++ b/sys/pc98/i386/machdep.c
@@ -423,6 +423,8 @@ cpu_startup(dummy)
 		TAILQ_INIT(&callwheel[i]);
 	}
 
+	mtx_init(&callout_lock, "callout", MTX_SPIN);
+
 #if defined(USERCONFIG)
 	userconfig();
 	cninit();		/* the preferred console may have changed */
diff --git a/sys/pc98/pc98/machdep.c b/sys/pc98/pc98/machdep.c
index caa579c664cd..08cd9c80dfdd 100644
--- a/sys/pc98/pc98/machdep.c
+++ b/sys/pc98/pc98/machdep.c
@@ -423,6 +423,8 @@ cpu_startup(dummy)
 		TAILQ_INIT(&callwheel[i]);
 	}
 
+	mtx_init(&callout_lock, "callout", MTX_SPIN);
+
 #if defined(USERCONFIG)
 	userconfig();
 	cninit();		/* the preferred console may have changed */