diff --git a/src/os/gfx/linux/os_gfx_linux.h b/src/os/gfx/linux/os_gfx_linux.h
index 96341575..4a562ae5 100644
--- a/src/os/gfx/linux/os_gfx_linux.h
+++ b/src/os/gfx/linux/os_gfx_linux.h
@@ -14,6 +14,17 @@
 #include <X11/keysym.h>
 #include <X11/keysymdef.h>
 
+////////////////////////////////
+//~ rjf: Prototypes (which seem to sometimes be missing)
+
+typedef struct _XComposeStatus
+{
+  XPointer compose_ptr;
+  int chars_matched;
+}
+XComposeStatus;
+int XLookupString(XKeyEvent *event_struct, char *buffer_return, int bytes_buffer, KeySym *keysym_return, XComposeStatus *status_in_out);
+
 ////////////////////////////////
 //~ rjf: Window State