diff --git a/BUILD b/BUILD
index 4e03973..1d3c2e1 100644
--- a/BUILD
+++ b/BUILD
@@ -44,6 +44,7 @@
 cc_library(
     name = "time_source",
     hdrs = ["time_source.h"],
+    deps = [":protocol"],
 )
 
 cc_library(