diff --git a/sdk/head/units.h b/sdk/head/units.h
index 1a038ca..e4dd8c3 100644
--- a/sdk/head/units.h
+++ b/sdk/head/units.h
@@ -15,5 +15,8 @@
 
 /* Time units */
 #define UNIT_FS_PER_MS 1000000000000ULL
+#define FSEC_PER_SECOND 1000000000000000ULL
+#define NSEC_PER_SECOND 1000000000ULL
+#define USEC_PER_SECOND 1000000ULL
 
 #endif  /* !_SDK_UNITS_H_ */