Fix typo.
diff --git a/PC/pyconfig.h b/PC/pyconfig.h
index dcfc36c..33777dc 100644
--- a/PC/pyconfig.h
+++ b/PC/pyconfig.h
@@ -29,7 +29,7 @@
 
 /* Visual Studio 2005 introduces deprecation warnings for
    "insecure" and POSIX functions. The insecure functions should
-   be replaces by *_s versions (according to Microsoft); the
+   be replaced by *_s versions (according to Microsoft); the
    POSIX functions by _* versions (which, according to Microsoft,
    would be ISO C conforming). Neither renaming is feasible, so
    we just silence the warnings. */