diff --git a/bacnet-stack/include/fifo.h b/bacnet-stack/include/fifo.h
index 2431c101..0e0fb648 100755
--- a/bacnet-stack/include/fifo.h
+++ b/bacnet-stack/include/fifo.h
@@ -75,6 +75,9 @@ bool FIFO_Add(
         uint8_t *data_bytes,
         unsigned count);
 
+void FIFO_Flush(
+        FIFO_BUFFER * b);
+
 /* note: buffer_len must be a power of two */
 void FIFO_Init(
         FIFO_BUFFER * b,