diff --git a/pngconf.h b/pngconf.h
index 8c56d40..78882ae 100644
--- a/pngconf.h
+++ b/pngconf.h
@@ -3,7 +3,7 @@
  *
  * libpng version 1.6.38.git
  *
- * Copyright (c) 2018-2019 Cosmin Truta
+ * Copyright (c) 2018-2022 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2016,2018 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@@ -180,8 +180,8 @@
  * compiler-specific macros to the values required to change the calling
  * conventions of the various functions.
  */
-#if defined(_Windows) || defined(_WINDOWS) || defined(WIN32) ||\
-    defined(_WIN32) || defined(__WIN32__) || defined(__CYGWIN__)
+#if defined(_WIN32) || defined(__WIN32__) || defined(__NT__) || \
+    defined(__CYGWIN__)
   /* Windows system (DOS doesn't support DLLs).  Includes builds under Cygwin or
    * MinGW on any architecture currently supported by Windows.  Also includes
    * Watcom builds but these need special treatment because they are not
diff --git a/pngpriv.h b/pngpriv.h
index a8e78e4..e4808a8 100644
--- a/pngpriv.h
+++ b/pngpriv.h
@@ -540,9 +540,8 @@
 #  include <alloc.h>
 #endif
 
-#if defined(WIN32) || defined(_Windows) || defined(_WINDOWS) || \
-    defined(_WIN32) || defined(__WIN32__)
-#  include <windows.h>  /* defines _WINDOWS_ macro */
+#if defined(_WIN32) || defined(__WIN32__) || defined(__NT__)
+#  include <windows.h>
 #endif
 #endif /* PNG_VERSION_INFO_ONLY */
 
@@ -551,13 +550,9 @@
  * functions that are passed far data must be model-independent.
  */
 
-/* Memory model/platform independent fns */
+/* Platform-independent functions */
 #ifndef PNG_ABORT
-#  ifdef _WINDOWS_
-#    define PNG_ABORT() ExitProcess(0)
-#  else
-#    define PNG_ABORT() abort()
-#  endif
+#  define PNG_ABORT() abort()
 #endif
 
 /* These macros may need to be architecture dependent. */
diff --git a/pngstruct.h b/pngstruct.h
index 8bdc7ce..e591d94 100644
--- a/pngstruct.h
+++ b/pngstruct.h
@@ -1,7 +1,7 @@
 
 /* pngstruct.h - header file for PNG reference library
  *
- * Copyright (c) 2018-2019 Cosmin Truta
+ * Copyright (c) 2018-2022 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@@ -334,18 +334,8 @@
    size_t current_buffer_size;       /* amount of data now in current_buffer */
    int process_mode;                 /* what push library is currently doing */
    int cur_palette;                  /* current push library palette index */
-
 #endif /* PROGRESSIVE_READ */
 
-#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
-/* For the Borland special 64K segment handler */
-   png_bytepp offset_table_ptr;
-   png_bytep offset_table;
-   png_uint_16 offset_table_number;
-   png_uint_16 offset_table_count;
-   png_uint_16 offset_table_count_free;
-#endif
-
 #ifdef PNG_READ_QUANTIZE_SUPPORTED
    png_bytep palette_lookup; /* lookup table for quantizing */
    png_bytep quantize_index; /* index translation for palette files */