diff --git a/Parser/grammar.c b/Parser/grammar.c
index 1f01562..659a151 100644
--- a/Parser/grammar.c
+++ b/Parser/grammar.c
@@ -9,6 +9,10 @@
 #include "token.h"
 #include "grammar.h"
 
+#ifdef RISCOS
+#include <unixlib.h>
+#endif
+
 extern int Py_DebugFlag;
 
 grammar *