diff --git a/rtc_base/BUILD.gn b/rtc_base/BUILD.gn
index 2476bca1f1..e96e6616a5 100644
--- a/rtc_base/BUILD.gn
+++ b/rtc_base/BUILD.gn
@@ -381,6 +381,7 @@ rtc_library("rtc_event") {
     ]
     deps = [
       ":checks",
+      "../api/units:time_delta",
       "system:rtc_export",  # Only Chromium's rtc::Event use RTC_EXPORT.
       "//base",  # Dependency on chromium's waitable_event.
     ]