diff --git a/lib/buffer.c b/lib/buffer.c
index 45e2e1c..b689549 100644
--- a/lib/buffer.c
+++ b/lib/buffer.c
@@ -322,7 +322,8 @@
 	      /* This should absolutely never occur. */
 	      zlog_err("%s: corruption detected: iov_small overflowed; "
 		       "head %p, tail %p, head->next %p",
-		       __func__, b->head, b->tail, b->head->next);
+		       __func__, (void *)b->head, (void *)b->tail,
+		       (void *)b->head->next);
 	      iov = XMALLOC(MTYPE_TMP, iov_alloc*sizeof(*iov));
 	      memcpy(iov, small_iov, sizeof(small_iov));
 	    }