diff --git a/sys/pc98/i386/machdep.c b/sys/pc98/i386/machdep.c
index e41899f4dc1..ed253cb970d 100644
--- a/sys/pc98/i386/machdep.c
+++ b/sys/pc98/i386/machdep.c
@@ -1764,7 +1764,7 @@ init386(first)
 	 */
 	mtx_init(&Giant, "Giant", MTX_DEF | MTX_RECURSE);
 	mtx_init(&sched_lock, "sched lock", MTX_SPIN | MTX_RECURSE);
-	mtx_init(&proc0.p_mtx, "process lock", MTX_DEF);
+	mtx_init(&proc0.p_mtx, "process lock", MTX_DEF|MTX_DUPOK);
 	mtx_init(&clock_lock, "clk", MTX_SPIN | MTX_RECURSE);
 	mtx_init(&icu_lock, "icu", MTX_SPIN | MTX_NOWITNESS);
 	mtx_lock(&Giant);
diff --git a/sys/pc98/pc98/machdep.c b/sys/pc98/pc98/machdep.c
index e41899f4dc1..ed253cb970d 100644
--- a/sys/pc98/pc98/machdep.c
+++ b/sys/pc98/pc98/machdep.c
@@ -1764,7 +1764,7 @@ init386(first)
 	 */
 	mtx_init(&Giant, "Giant", MTX_DEF | MTX_RECURSE);
 	mtx_init(&sched_lock, "sched lock", MTX_SPIN | MTX_RECURSE);
-	mtx_init(&proc0.p_mtx, "process lock", MTX_DEF);
+	mtx_init(&proc0.p_mtx, "process lock", MTX_DEF|MTX_DUPOK);
 	mtx_init(&clock_lock, "clk", MTX_SPIN | MTX_RECURSE);
 	mtx_init(&icu_lock, "icu", MTX_SPIN | MTX_NOWITNESS);
 	mtx_lock(&Giant);