diff --git a/sys/kern/kern_mutex.c b/sys/kern/kern_mutex.c
index 2d486531a373..00df083a494a 100644
--- a/sys/kern/kern_mutex.c
+++ b/sys/kern/kern_mutex.c
@@ -50,6 +50,7 @@
  *	6 capitalized : a member of the Jehovah's Witnesses 
  */
 
+#include "opt_ddb.h"
 #include "opt_witness.h"
 
 #include <sys/param.h>
@@ -67,6 +68,8 @@
 #include <machine/clock.h>
 #include <machine/cpu.h>
 
+#include <ddb/ddb.h>
+
 #include <vm/vm.h>
 #include <vm/vm_extern.h>
 
diff --git a/sys/kern/subr_turnstile.c b/sys/kern/subr_turnstile.c
index 2d486531a373..00df083a494a 100644
--- a/sys/kern/subr_turnstile.c
+++ b/sys/kern/subr_turnstile.c
@@ -50,6 +50,7 @@
  *	6 capitalized : a member of the Jehovah's Witnesses 
  */
 
+#include "opt_ddb.h"
 #include "opt_witness.h"
 
 #include <sys/param.h>
@@ -67,6 +68,8 @@
 #include <machine/clock.h>
 #include <machine/cpu.h>
 
+#include <ddb/ddb.h>
+
 #include <vm/vm.h>
 #include <vm/vm_extern.h>
 
diff --git a/sys/kern/subr_witness.c b/sys/kern/subr_witness.c
index 2d486531a373..00df083a494a 100644
--- a/sys/kern/subr_witness.c
+++ b/sys/kern/subr_witness.c
@@ -50,6 +50,7 @@
  *	6 capitalized : a member of the Jehovah's Witnesses 
  */
 
+#include "opt_ddb.h"
 #include "opt_witness.h"
 
 #include <sys/param.h>
@@ -67,6 +68,8 @@
 #include <machine/clock.h>
 #include <machine/cpu.h>
 
+#include <ddb/ddb.h>
+
 #include <vm/vm.h>
 #include <vm/vm_extern.h>