diff --git a/src/at/tid.gleam b/src/at/tid.gleam
index 4005eb9..6532b59 100644
--- a/src/at/tid.gleam
+++ b/src/at/tid.gleam
@@ -4,6 +4,7 @@ import gleam/dynamic/decode.{type Decoder}
 import gleam/int
 import gleam/json.{type Json}
 import gleam/order.{type Order}
+import gleam/string
 import gleam/time/timestamp.{type Timestamp}
 
 // TYPES -----------------------------------------------------------------------
@@ -85,16 +86,19 @@ pub fn next(tid: Tid) -> Tid {
 @external(javascript, "./tid_ffi.mjs", "next")
 fn do_next(microseconds: Int) -> Int
 
-/// Attempt to parse a [`Tid`](#Tid) from a base32-sortable string like `"3jzfcijpj2z2a"`.
-/// In particular, an encoded [`Tid`](#Tid) will always be 13 characters long and
-/// contain only the characters `234567abcdefghijklmnopqrstuvwxyz`.
+/// Attempt to parse a [`Tid`](#Tid) from a base32-sortable string.
 /// 
 pub fn from_string(value: String) -> Result(Tid, Nil) {
-  case parse_tid_string(value) {
-    Ok(<<0:int-size(1), microseconds:int-size(53), clock:int-size(10)>>) ->
-      Ok(Tid(microseconds:, clock:))
+  case string.length(value) == 13 {
+    True ->
+      case parse_tid_string(value) {
+        Ok(<<0:int-size(1), microseconds:int-size(53), clock:int-size(10)>>) ->
+          Ok(Tid(microseconds:, clock:))
 
-    Ok(_) | Error(_) -> Error(Nil)
+        Ok(_) | Error(_) -> Error(Nil)
+      }
+
+    False -> Error(Nil)
   }
 }