diff --git a/ext/mysql/libmysql/config-win.h b/ext/mysql/libmysql/config-win.h
index 8567be406db..5d4d40d98bf 100644
--- a/ext/mysql/libmysql/config-win.h
+++ b/ext/mysql/libmysql/config-win.h
@@ -239,7 +239,7 @@ inline double ulonglong2double(ulonglong value)
 #define HAVE_ALLOCA
 #define HAVE_STRPBRK
 #define HAVE_STRSTR
-#define HAVE_COMPRESS
+/* #define HAVE_COMPRESS     -- not with PHP, please */
 
 #ifdef NOT_USED
 #define HAVE_SNPRINTF		/* Gave link error */
diff --git a/ext/mysql/libmysql/update_sources b/ext/mysql/libmysql/update_sources
index 8a3919022e8..573129b020e 100755
--- a/ext/mysql/libmysql/update_sources
+++ b/ext/mysql/libmysql/update_sources
@@ -89,6 +89,8 @@ sub diff_files {
     else
     {
       print STDERR "DIFF: $f\n";
+      $f eq 'config-win.h' and
+	print STDERR "/n/nDon't forget to undefine HAVE_COMPRESS in $f/n/n/n";
     }
   }
 }