diff --git a/src/INSTALL b/src/INSTALL
index a827fa1..99f1047 100644
--- a/src/INSTALL
+++ b/src/INSTALL
@@ -221,8 +221,8 @@
 be considered for the next release.  If at some point `config.cache'
 contains results you don't want to keep, you may remove or edit it.
 
-   The file `configure.in' is used to create `configure' by a program
-called `autoconf'.  You only need `configure.in' if you want to change
+   The file `configure.ac' is used to create `configure' by a program
+called `autoconf'.  You only need `configure.ac' if you want to change
 it or regenerate `configure' using a newer version of `autoconf'.
 
 The simplest way to compile this package is:
diff --git a/src/Makefile b/src/Makefile
index fef53af..5c788cc 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -690,8 +690,8 @@
 #####################################################
 
 ### Uncomment things here only if the values chosen by configure are wrong.
-### It's better to adjust configure.in and "make autoconf", if you can!
-### Then send the required changes to configure.in to the bugs list.
+### It's better to adjust configure.ac and "make autoconf", if you can!
+### Then send the required changes to configure.ac to the bugs list.
 
 ### (1) BSD/OS 2.0.1, 2.1 or 3.0 using shared libraries
 ###
@@ -1832,7 +1832,7 @@
 # - DO NOT RUN autoconf MANUALLY!  It will overwrite ./configure instead of
 #   producing auto/configure.
 # - autoconf is not run automatically, because a patch usually changes both
-#   configure.in and auto/configure but can't update the timestamps.  People
+#   configure.ac and auto/configure but can't update the timestamps.  People
 #   who do not have (the correct version of) autoconf would run into trouble.
 #
 # Two tricks are required to make autoconf put its output in the "auto" dir:
diff --git a/src/blowfish.c b/src/blowfish.c
index ac9b088..eaf0b9e 100644
--- a/src/blowfish.c
+++ b/src/blowfish.c
@@ -38,7 +38,7 @@
   /* MS-Windows is always little endian */
 #else
 # ifdef HAVE_CONFIG_H
-   /* in configure.in AC_C_BIGENDIAN() defines WORDS_BIGENDIAN when needed */
+   /* in configure.ac AC_C_BIGENDIAN() defines WORDS_BIGENDIAN when needed */
 # else
    error!
    Please change this code to define WORDS_BIGENDIAN for big-endian machines.
diff --git a/src/channel.c b/src/channel.c
index aa82d71..1ddb1ec 100644
--- a/src/channel.c
+++ b/src/channel.c
@@ -19,7 +19,7 @@
 # define CH_HAS_GUI (gui.in_use || gui.starting)
 #endif
 
-/* Note: when making changes here also adjust configure.in. */
+/* Note: when making changes here also adjust configure.ac. */
 #ifdef WIN32
 /* WinSock API is separated from C API, thus we can't use read(), write(),
  * errno... */
diff --git a/src/config.h.in b/src/config.h.in
index 62427e2..5baac7d 100644
--- a/src/config.h.in
+++ b/src/config.h.in
@@ -1,6 +1,6 @@
 /*
- * config.h.in.  Generated automatically from configure.in by autoheader, and
- * manually changed after that.
+ * config.h.in.  Originally generated automatically from configure.ac by
+ * autoheader and manually changed after that.
  */
 
 /* Define if we have EBCDIC code */
diff --git a/src/configure.in b/src/configure.ac
similarity index 99%
rename from src/configure.in
rename to src/configure.ac
index 43bf9ad..f6a4469 100644
--- a/src/configure.in
+++ b/src/configure.ac
@@ -1,4 +1,4 @@
-dnl configure.in: autoconf script for Vim
+dnl configure.ac: autoconf script for Vim
 
 dnl Process this file with autoconf 2.12 or 2.13 to produce "configure".
 dnl Should also work with autoconf 2.54 and later.
diff --git a/src/main.aap b/src/main.aap
index bedbbb5..19bc97d 100644
--- a/src/main.aap
+++ b/src/main.aap
@@ -22,11 +22,11 @@
     # A U T O C O N F
     #
 
-    # Run autoconf when configure.in has been changed since it was last run.
+    # Run autoconf when configure.ac has been changed since it was last run.
     # This is skipped when the signatures in "mysign" are up-to-date.  When
     # there is no autoconf program skip this (the signature is often the only
     # thing that's outdated)
-    auto/configure {signfile = mysign} : configure.in
+    auto/configure {signfile = mysign} : configure.ac
         @if not program_path("autoconf"):
             :print Can't find autoconf, using existing configure script.
         @else:
diff --git a/src/mysign b/src/mysign
index 42b6cbb..fc751c0 100644
--- a/src/mysign
+++ b/src/mysign
@@ -1 +1 @@
-=auto/configure-lastupdate=1178970549.78-@buildcheck=dfc15c059b7ce88a951584995c49a201=configure.in@md5=e0d6e9a7d7b986d63ce4e8e7362fd0b9
+=auto/configure-lastupdate=1178970549.78-@buildcheck=dfc15c059b7ce88a951584995c49a201=configure.ac@md5=e0d6e9a7d7b986d63ce4e8e7362fd0b9
diff --git a/src/os_unix.c b/src/os_unix.c
index 5d5b151..6197c3f 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -265,7 +265,7 @@
  * that describe the signals. That is nearly what we want here.  But
  * autoconf does only check for sys_siglist (without the underscore), I
  * do not want to change everything today.... jw.
- * This is why AC_DECL_SYS_SIGLIST is commented out in configure.in
+ * This is why AC_DECL_SYS_SIGLIST is commented out in configure.ac.
  */
 #endif
 
diff --git a/src/version.c b/src/version.c
index 3071edc..e851922 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    82,
+/**/
     81,
 /**/
     80,