diff --git a/rfb/Timer.cxx b/rfb/Timer.cxx
index 59d250e..66fd2b1 100644
--- a/rfb/Timer.cxx
+++ b/rfb/Timer.cxx
@@ -29,6 +29,11 @@
 #include <rfb/util.h>
 #include <rfb/LogWriter.h>
 
+// XXX Lynx/OS 2.3: proto for gettimeofday()
+#ifdef Lynx
+#include <sys/proto.h>
+#endif
+
 using namespace rfb;
 
 #ifndef __NO_DEFINE_VLOG__
diff --git a/tx/TXCheckbox.h b/tx/TXCheckbox.h
index 3c2a23b..0880b38 100644
--- a/tx/TXCheckbox.h
+++ b/tx/TXCheckbox.h
@@ -68,7 +68,7 @@
   // setText() changes the text in the checkbox.
   void setText(const char* text_) {
     if (text) free(text);
-    text = strdup(text_);
+    text = strdup((char*)text_);
     int textWidth = XTextWidth(defaultFS, text, strlen(text));
     int textHeight = (defaultFS->ascent + defaultFS->descent);
     int newWidth = __rfbmax(width(), textWidth + xPad*2 + boxPad*2 + boxSize);
diff --git a/tx/TXDialog.h b/tx/TXDialog.h
index 0bfd88a..c8d601c 100644
--- a/tx/TXDialog.h
+++ b/tx/TXDialog.h
@@ -31,6 +31,11 @@
 #include "TXWindow.h"
 #include <errno.h>
 
+// XXX Lynx/OS 2.3: protos for bzero(), select()
+#ifdef Lynx
+#include <sys/proto.h>
+#endif
+
 class TXDialog : public TXWindow, public TXDeleteWindowCallback {
 public:
   TXDialog(Display* dpy, int width, int height, const char* name,
diff --git a/tx/TXEntry.h b/tx/TXEntry.h
index 9002957..1785a5f 100644
--- a/tx/TXEntry.h
+++ b/tx/TXEntry.h
@@ -33,6 +33,9 @@
 #ifndef XK_ISO_Left_Tab
 #define	XK_ISO_Left_Tab					0xFE20
 #endif
+#ifndef XK_KP_Delete
+#define XK_KP_Delete					0xFF9F
+#endif
 
 // TXEntryCallback's entryCallback() method is called when one of three special
 // key presses have happened: Enter/Return, forward tab, or backward tab.