diff --git a/cmd/zdb/zdb.c b/cmd/zdb/zdb.c
index 4434f31a3591..0d3043f40d9e 100644
--- a/cmd/zdb/zdb.c
+++ b/cmd/zdb/zdb.c
@@ -2824,9 +2824,11 @@ dump_bookmarks(objset_t *os, int verbosity)
 	    zap_cursor_advance(&zc)) {
 		char osname[ZFS_MAX_DATASET_NAME_LEN];
 		char buf[ZFS_MAX_DATASET_NAME_LEN];
+		int len;
 		dmu_objset_name(os, osname);
-		VERIFY3S(0, <=, snprintf(buf, sizeof (buf), "%s#%s", osname,
-		    attr.za_name));
+		len = snprintf(buf, sizeof (buf), "%s#%s", osname,
+		    attr.za_name);
+		VERIFY3S(len, <, ZFS_MAX_DATASET_NAME_LEN);
 		(void) dump_bookmark(dp, buf, verbosity >= 5, verbosity >= 6);
 	}
 	zap_cursor_fini(&zc);