diff --git a/content/docs/rfcs/13/README.md b/content/docs/rfcs/13/README.md
index bc7371725..0f004c4d7 100644
--- a/content/docs/rfcs/13/README.md
+++ b/content/docs/rfcs/13/README.md
@@ -53,8 +53,8 @@ syntax = "proto3";
 
 message Index {
   bytes digest = 1;
-  double receiverTime = 2;
-  double senderTime = 3;
+  int64 receiverTime = 2;
+  int64 senderTime = 3;
 }
 
 message PagingInfo {
@@ -101,8 +101,8 @@ message HistoryRPC {
 To perform pagination, each `WakuMessage` stored at a node running the `13/WAKU2-STORE` protocol is associated with a unique `Index` that encapsulates the following parts. 
 - `digest`:  a sequence of bytes representing the SHA256 hash of a `WakuMessage`.
   The hash is computed over the concatenation of `contentTopic` and `payload` fields of a `WakuMessage` (see [14/WAKU2-MESSAGE](/spec/14)).
-- `receiverTime`: the UNIX time at which the waku message is received by the receiving node.
-- `senderTime`: the UNIX time at which the waku message is generated by its sender.
+- `receiverTime`: the UNIX time in nanoseconds at which the waku message is received by the receiving node.
+- `senderTime`: the UNIX time in nanoseconds at which the waku message is generated by its sender.
 
 ### PagingInfo
 
diff --git a/content/docs/rfcs/14/README.md b/content/docs/rfcs/14/README.md
index d58d2b6bd..19f243ce2 100644
--- a/content/docs/rfcs/14/README.md
+++ b/content/docs/rfcs/14/README.md
@@ -35,8 +35,7 @@ The `version` field MAY be filled out to allow for various types of payload encr
 Omitting it means the version is 0.
 
 The `timestamp` field MAY be filled out to signify the time at which the message is generated by its sender. 
-This field holds the Unix epoch time in seconds. 
-The fractional part represents the sub-seconds. 
+This field holds the Unix epoch time in nanoseconds. 
 Omitting it means the timestamp is unspecified.
 
 ## Payloads
@@ -50,7 +49,7 @@ message WakuMessage {
   bytes payload = 1;
   string contentTopic = 2;
   uint32 version = 3;
-  double timestamp = 4;
+  int64 timestamp = 4;
 }
 ```