diff --git a/PC/pyconfig.h b/PC/pyconfig.h
index 2444c8a..ed6c84f7 100644
--- a/PC/pyconfig.h
+++ b/PC/pyconfig.h
@@ -344,7 +344,7 @@
 #	define SIZEOF_FPOS_T 8
 #	define SIZEOF_HKEY 8
 #	define SIZEOF_SIZE_T 8
-/* configure.in defines HAVE_LARGEFILE_SUPPORT iff HAVE_LONG_LONG,
+/* configure.ac defines HAVE_LARGEFILE_SUPPORT iff HAVE_LONG_LONG,
    sizeof(off_t) > sizeof(long), and sizeof(PY_LONG_LONG) >= sizeof(off_t).
    On Win64 the second condition is not true, but if fpos_t replaces off_t
    then this is true. The uses of HAVE_LARGEFILE_SUPPORT imply that Win64