diff --git a/5C.md b/5C.md
index 218229ca..6d9455af 100644
--- a/5C.md
+++ b/5C.md
@@ -182,7 +182,7 @@ Add an id to the `ids` filter. It must be a pointer to a 32-byte buffer.
 
 Same as `req_add_id` but with a hex-encoded id string. Length is assumed to be 64 characters.
 
-### `nostr.req_add_kind(req: i32, kind: i32) -> void`
+### `nostr.req_add_kind(req: i32, kind: u32) -> void`
 
 Add a kind integer to the `kinds` filter.
 
@@ -196,15 +196,15 @@ Same as `req_add_tag` but the value is a pointer to the 32-byte binary buffer th
 
 Hosts may deduplicate filter values (authors, ids, kinds, and tag values) when the module adds the same value more than once via `req_add_*`.
 
-### `nostr.req_set_limit(req: i32, limit: i32) -> void`
+### `nostr.req_set_limit(req: i32, limit: u32) -> void`
 
 Sets the `"limit"` attribute of the filter.
 
-### `nostr.req_set_since(req: i32, timestamp: i32) -> void`
+### `nostr.req_set_since(req: i32, timestamp: u32) -> void`
 
 Sets the `"since"` attribute of the filter.
 
-### `nostr.req_set_until(req: i32, timestamp: i32) -> void`
+### `nostr.req_set_until(req: i32, timestamp: u32) -> void`
 
 Sets the `"until"` attribute of the filter.
 
@@ -253,11 +253,11 @@ Returns a pointer to a 32-byte buffer containing the public key of the event aut
 
 Returns a pointer to a 64-character string containing the hex public key of the event author.
 
-### `nostr.event_get_kind(event_handle: i32) -> i32`
+### `nostr.event_get_kind(event_handle: i32) -> u32`
 
 Returns the kind integer directly.
 
-### `nostr.event_get_created_at(event_handle: i32) -> i32`
+### `nostr.event_get_created_at(event_handle: i32) -> u32`
 
 Returns the unix timestamp directly.
 
@@ -265,11 +265,11 @@ Returns the unix timestamp directly.
 
 Returns a pointer to a buffer containing the event content (follows the String Convention above).
 
-### `nostr.event_get_tag_count(event_handle: i32) -> i32`
+### `nostr.event_get_tag_count(event_handle: i32) -> u32`
 
 Returns the total number of tags on this event.
 
-### `nostr.event_get_tag_item_count(event_handle: i32, tag_index: i32) -> i32`
+### `nostr.event_get_tag_item_count(event_handle: i32, tag_index: i32) -> u32`
 
 Returns the number of items in the tag at `tag_index`; or `0` if such tag doesn't exist.