diff --git a/include/ndn-cpp/c/common.h b/include/ndn-cpp/c/common.h
index 54a080c..0cb68d5 100644
--- a/include/ndn-cpp/c/common.h
+++ b/include/ndn-cpp/c/common.h
@@ -19,12 +19,12 @@
 /**
  * A time interval represented as the number of milliseconds.
  */
-typedef double ndn_Milliseconds;
+typedef int64_t ndn_Milliseconds;
    
 /**
  * The calendar time represented as the number of milliseconds since 1/1/1970.
  */
-typedef double ndn_MillisecondsSince1970;
+typedef int64_t ndn_MillisecondsSince1970;
 
 #ifdef __cplusplus
 }