diff --git a/Source/kwsys/ProcessUNIX.c b/Source/kwsys/ProcessUNIX.c
index fc9e8bf67..b9af2f1f5 100644
--- a/Source/kwsys/ProcessUNIX.c
+++ b/Source/kwsys/ProcessUNIX.c
@@ -47,6 +47,12 @@ do.
 
 */
 
+#if defined(__CYGWIN__)
+/* Increase the file descriptor limit for select() before including
+   related system headers. (Default: 64) */
+# define FD_SETSIZE 16384
+#endif
+
 #include <stddef.h>    /* ptrdiff_t */
 #include <stdio.h>     /* snprintf */
 #include <stdlib.h>    /* malloc, free */
diff --git a/Source/kwsys/SystemInformation.cxx b/Source/kwsys/SystemInformation.cxx
index f057e0fcb..9e2a93d7c 100644
--- a/Source/kwsys/SystemInformation.cxx
+++ b/Source/kwsys/SystemInformation.cxx
@@ -130,7 +130,7 @@ typedef int siginfo_t;
 #   define KWSYS_SYSTEMINFORMATION_IMPLEMENT_FQDN
 #  endif
 # endif
-# if defined(__GNUG__)
+# if defined(__GNUC__)
 #  include <execinfo.h>
 #  if !(defined(__LSB_VERSION__) && __LSB_VERSION__ < 41)
 #   define KWSYS_SYSTEMINFORMATION_HAVE_BACKTRACE