diff --git a/Source/kwsys/SystemTools.cxx b/Source/kwsys/SystemTools.cxx
index ebb26dca0..038366186 100644
--- a/Source/kwsys/SystemTools.cxx
+++ b/Source/kwsys/SystemTools.cxx
@@ -58,6 +58,27 @@
 #include <termios.h>
 #endif
 
+// This is a hack to prevent warnings about these functions being
+// declared but not referenced.
+#if defined(__sgi) && !defined(__GNUC__)
+# include <sys/termios.h>
+namespace KWSYS_NAMESPACE
+{
+class SystemToolsHack
+{
+public:
+  enum
+  {
+    Ref1 = sizeof(cfgetospeed(0)),
+    Ref2 = sizeof(cfgetispeed(0)),
+    Ref3 = sizeof(tcgetattr(0, 0)),
+    Ref4 = sizeof(tcsetattr(0, 0, 0)),
+    Ref5 = sizeof(cfsetospeed(0,0)),
+    Ref6 = sizeof(cfsetispeed(0,0))
+  };
+};
+}
+#endif
 
 #if defined(_WIN32) && (defined(_MSC_VER) || defined(__BORLANDC__) || defined(__MINGW32__))
 #include <io.h>