diff --git a/src/test/test-sizeof.c b/src/test/test-sizeof.c
index 18378b0450..ea0c58770e 100644
--- a/src/test/test-sizeof.c
+++ b/src/test/test-sizeof.c
@@ -5,6 +5,7 @@
 #include <string.h>
 #include <sys/resource.h>
 #include <sys/socket.h>
+#include <sys/timex.h>
 #include <sys/types.h>
 
 #define __STDC_WANT_IEC_60559_TYPES_EXT__