diff --git a/lib/libzpool/kernel.c b/lib/libzpool/kernel.c
index f22ad56b5..0f39e0d72 100644
--- a/lib/libzpool/kernel.c
+++ b/lib/libzpool/kernel.c
@@ -813,7 +813,8 @@ __dprintf(boolean_t dprint, const char *file, const char *func,
 		if (dprintf_find_string("pid"))
 			(void) printf("%d ", getpid());
 		if (dprintf_find_string("tid"))
-			(void) printf("%u ", (uint_t)pthread_self());
+			(void) printf("%ju ",
+			    (uintmax_t)(uintptr_t)pthread_self());
 		if (dprintf_find_string("cpu"))
 			(void) printf("%u ", getcpuid());
 		if (dprintf_find_string("time"))