1 files changed, 1 insertions, 1 deletions
diff --git a/rubyio.h b/rubyio.h
index 6509e3e7c1..d3d93ef6b7 100644
--- a/rubyio.h
+++ b/rubyio.h
@@ -23,7 +23,7 @@ typedef struct OpenFile {
     int pid;			/* child's pid (for pipes) */
     int lineno;			/* number of lines read */
     char *path;			/* pathname for file */
-    void (*finalize)();		/* finalize proc */
+    void (*finalize) _((struct OpenFile*)); /* finalize proc */
 } OpenFile;
 
 #define FMODE_READABLE  1