diff --git a/third_party/cereal.BUILD b/third_party/cereal.BUILD
index 58fa91aa..3bdd661a 100644
--- a/third_party/cereal.BUILD
+++ b/third_party/cereal.BUILD
@@ -15,5 +15,7 @@ package(
 cc_library(
     name = "cereal",
     hdrs = glob(["include/**"]),
+    defines = ["CEREAL_THREAD_SAFE=1"],
     includes = ["include"],
+    linkopts = ["-lpthread"],
 )