diff --git a/harbour/ChangeLog b/harbour/ChangeLog
index ad02cbf556..9397014bcf 100644
--- a/harbour/ChangeLog
+++ b/harbour/ChangeLog
@@ -1,3 +1,9 @@
+19990911-20:25 EDT David G. Holm <dholm@jsd-llc.com>
+  * source/rtl/tone.c
+    ! Added '|| defined(__CYGWIN__)' to the #if block for HARBOUR_GCC_OS2
+      and _Windows for calculating the value for temp for each pass of the
+      tone duration timing loop.
+  
 19990911-07:42 EDT Paul Tucker <ptucker@sympatico.ca>
   * makefile.vc
     added new files for compiler to exe generation section
diff --git a/harbour/source/rtl/tone.c b/harbour/source/rtl/tone.c
index 9e0d75aa08..7c4a9fbe2b 100644
--- a/harbour/source/rtl/tone.c
+++ b/harbour/source/rtl/tone.c
@@ -158,7 +158,7 @@ void hb_tone( double frequency, double duration )
 #endif
    while( duration > 0.0 )
    {
-#if defined(HARBOUR_GCC_OS2) || defined(_Windows)
+#if defined(HARBOUR_GCC_OS2) || defined(_Windows) || defined(__CYGWIN__)
       temp = MIN( MAX ( 0, duration ), ULONG_MAX );
 #elif defined(OS2) || defined(__BORLANDC__) || defined(__DJGPP__)
       temp = MIN( MAX ( 0, duration ), USHRT_MAX );