diff --git a/sys/kern/vfs_bio.c b/sys/kern/vfs_bio.c
--- a/sys/kern/vfs_bio.c
+++ b/sys/kern/vfs_bio.c
@@ -160,7 +160,7 @@
 
 caddr_t __read_mostly unmapped_buf;
 #ifdef INVARIANTS
-caddr_t	poisoned_buf = (void *)-1;
+void *poisoned_buf = (void *)-1;
 #endif
 
 /* Used below and for softdep flushing threads in ufs/ffs/ffs_softdep.c */
diff --git a/sys/sys/kassert.h b/sys/sys/kassert.h
--- a/sys/sys/kassert.h
+++ b/sys/sys/kassert.h
@@ -51,11 +51,11 @@
  */
 #ifdef	INVARIANTS
 
-extern caddr_t poisoned_buf;
+extern void *poisoned_buf;
 #define DEBUG_POISON_POINTER_VALUE poisoned_buf
 
 #define DEBUG_POISON_POINTER(x) ({				\
-	x = (void *)(DEBUG_POISON_POINTER_VALUE);		\
+	x = (DEBUG_POISON_POINTER_VALUE);			\
 })
 
 #else