diff --git a/advent.h b/advent.h
index 5e9871d..09f5ad9 100644
--- a/advent.h
+++ b/advent.h
@@ -231,7 +231,7 @@ extern int suspend(void);
 extern int resume(void);
 extern int restore(FILE *);
 extern long initialise(void);
-extern int action(command_t command);
+extern int action(command_t);
 extern void state_change(obj_t, int);
 extern bool is_valid(struct game_t);
 
diff --git a/main.c b/main.c
index 3f2776c..027f92d 100644
--- a/main.c
+++ b/main.c
@@ -972,6 +972,13 @@ static void listobjects(void)
     }
 }
 
+void clear_command(command_t *cmd)
+{
+    cmd->verb = ACT_NULL;
+    game.oldobj = cmd->obj;
+    cmd->obj = NO_OBJECT;
+}
+
 static bool do_command()
 /* Get and execute a command */
 {