diff --git a/ANNOUNCE b/ANNOUNCE
index eb4d988fe5db880e401ab023256c8afe590103bc..787325de60836608e002efc7f2138f417206a75b 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -137,7 +137,9 @@ Version 1.6.0beta07 [January 28, 2012]
     set CMAKE_LIBRARY_OUTPUT_DIRECTORY to "lib" on all platforms (C. Yapp).
   Freeze libtool files in the 'scripts' directory. This version of autogen.sh
     attempts to dissuade people from running it when it is not, or should not,
-    be necessary.
+    be necessary.  In fact, autogen.sh does not work when run in a libpng
+    directory extracted from atar distribution anymore. You must run it in
+    a GIT clone instead.
   Added two images to contrib/pngsuite (1-bit and 2-bit transparent grayscale),
     and renamed three whose names were inconsistent with those in
     pngsuite/README.txt.
@@ -162,6 +164,8 @@ Version 1.6.0beta08 [February 1, 2012]
   Updated "ftbb*.png" list in the owatcom and vstudio projects.
   Fixed 'prefix' builds on clean systems. The generation of pngprefix.h
     should not require itself.
+  Updated INSTALL to explain that autogen.sh must be run in a GIT clone,
+    not in a libpng directory extracted from a tar distribution.
 
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diff --git a/CHANGES b/CHANGES
index 02cfd5afb73eb94478758418233d9ecee1d977ae..6c9cf78e7862ce474d5dec3a8e40c29c998c95a5 100644
--- a/CHANGES
+++ b/CHANGES
@@ -3888,7 +3888,9 @@ Version 1.6.0beta07 [January 28, 2012]
     set CMAKE_LIBRARY_OUTPUT_DIRECTORY to "lib" on all platforms (C. Yapp).
   Freeze libtool files in the 'scripts' directory. This version of autogen.sh
     attempts to dissuade people from running it when it is not, or should not,
-    be necessary.
+    be necessary.  In fact, autogen.sh does not work when run in a libpng
+    directory extracted from atar distribution anymore. You must run it in
+    a GIT clone instead.
   Added two images to contrib/pngsuite (1-bit and 2-bit transparent grayscale),
     and renamed three whose names were inconsistent with those in
     pngsuite/README.txt.
@@ -3913,6 +3915,8 @@ Version 1.6.0beta08 [February 1, 2012]
   Updated "ftbb*.png" list in the owatcom and vstudio projects.
   Fixed 'prefix' builds on clean systems. The generation of pngprefix.h
     should not require itself.
+  Updated INSTALL to explain that autogen.sh must be run in a GIT clone,
+    not in a libpng directory extracted from a tar distribution.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit