Typo repair.
diff --git a/Doc/api/concrete.tex b/Doc/api/concrete.tex
index 9a5d3eb..8390a72 100644
--- a/Doc/api/concrete.tex
+++ b/Doc/api/concrete.tex
@@ -635,7 +635,7 @@
     \lineiii{\%ld}{long}{Exactly equivalent to \code{printf("\%ld")}.}
     \lineiii{\%lu}{unsigned long}{Exactly equivalent to \code{printf("\%lu")}.}
     \lineiii{\%zd}{Py_ssize_t}{Exactly equivalent to \code{printf("\%zd")}.}
-    \lineiii{\%zu}{ssize_t}{Exactly equivalent to \code{printf("\%zu")}.}
+    \lineiii{\%zu}{size_t}{Exactly equivalent to \code{printf("\%zu")}.}
     \lineiii{\%i}{int}{Exactly equivalent to \code{printf("\%i")}.}
     \lineiii{\%x}{int}{Exactly equivalent to \code{printf("\%x")}.}
     \lineiii{\%s}{char*}{A null-terminated C character array.}