diff --git a/absl/base/internal/unscaledcycleclock.cc b/absl/base/internal/unscaledcycleclock.cc
index 7b79d19e..b1c396c6 100644
--- a/absl/base/internal/unscaledcycleclock.cc
+++ b/absl/base/internal/unscaledcycleclock.cc
@@ -24,8 +24,13 @@
 #ifdef __GLIBC__
 #include <sys/platform/ppc.h>
 #elif defined(__FreeBSD__)
-#include <sys/sysctl.h>
+// clang-format off
+// This order does actually matter =(.
 #include <sys/types.h>
+#include <sys/sysctl.h>
+// clang-format on
+
+#include "absl/base/call_once.h"
 #endif
 #endif