diff --git a/common.h b/common.h
index 874f2d7..31a0014 100644
--- a/common.h
+++ b/common.h
@@ -40,7 +40,7 @@ struct circ_buf {
 	int quit;
 	int head;
 	int tail;
-	int data[MAX_ITEMS];
+	int data[MAX_ITEMS+1];
 };
 
 #endif /* ifndef COMMON_H */