diff --git a/ChangeLog.txt b/ChangeLog.txt
index ae0e7ef6d1..44556341ed 100644
--- a/ChangeLog.txt
+++ b/ChangeLog.txt
@@ -7,6 +7,11 @@
    Entries may not always be in chronological/commit order.
    See license at the end of file. */
 
+2025-01-30 03:34 UTC+0100 Przemyslaw Czerpak (druzus/at/poczta.onet.pl)
+  * include/hbdefs.h
+    * added final workarounds for OpenWatcom 2.0 bug in 64bit expressions used
+      in #[el]if statements
+
 2025-01-30 02:48 UTC+0100 Przemyslaw Czerpak (druzus/at/poczta.onet.pl)
   * contrib/sddsqlt3/core.c
   * include/hbdefs.h
diff --git a/include/hbdefs.h b/include/hbdefs.h
index fb32a9bbb6..f0a17a6ad6 100644
--- a/include/hbdefs.h
+++ b/include/hbdefs.h
@@ -511,6 +511,9 @@ typedef HB_U32       HB_SYMCNT;
 #  define HB_ULL( num )          num##ULL
 #endif
 
+#if defined( __WATCOMC__ ) && LONGLONG_MAX < LONG_MAX
+   #define HB_WATCOM_64BUG
+#endif
 
 /* HB_*_EXPLENGTH() macros are used by HVM to set the size of
  * math operations, HB_*_LENGTH() macros are used when new
@@ -537,10 +540,10 @@ typedef HB_U32       HB_SYMCNT;
 #endif
 
 #if ! defined( HB_LONG_LONG_OFF )
-#  if HB_VMLONG_MAX > HB_LL( 9999999999 )
+#  if HB_VMLONG_MAX > HB_LL( 9999999999 ) || defined( HB_WATCOM_64BUG )
 #     define HB_LONG_LENGTH( l )    ( ( (l) < -999999999 || (l) > HB_LL( 9999999999 ) ) ? 20 : 10 )
 #  endif
-#  if HB_VMINT_MAX > HB_LL( 9999999999 )
+#  if HB_VMINT_MAX > HB_LL( 9999999999 ) && ! defined( HB_WATCOM_64BUG )
 #     define HB_INT_EXPLENGTH( i )  HB_LONG_LENGTH( i )
 #  endif
 #endif