diff --git a/src/core/time.h b/src/core/time.h
index 1ee95778..b754b06e 100644
--- a/src/core/time.h
+++ b/src/core/time.h
@@ -5,6 +5,7 @@
 #include <time.h>
 
 #define NS_PER_SEC INT64_C(1000000000)
+#define NS_PER_MS INT64_C(1000000)
 
 int64_t time_nanoseconds();