diff --git a/pep-0393.txt b/pep-0393.txt
index 18ecaa4c4..5e121ba6f 100644
--- a/pep-0393.txt
+++ b/pep-0393.txt
@@ -71,7 +71,7 @@ These fields have the following interpretations:
 - length: number of code points in the string (result of sq_length)
 - str: shortest-form representation of the unicode string; the lower
   two bits of the pointer indicate the specific form:
-  01 => 1 byte (Latin-1); 11 => 2 byte (UCS-2); 11 => 4 byte (UCS-4);
+  01 => 1 byte (Latin-1); 10 => 2 byte (UCS-2); 11 => 4 byte (UCS-4);
   00 => null pointer
 
   The string is null-terminated (in its respective representation).