diff --git a/bacnet-stack/include/bvlc.h b/bacnet-stack/include/bvlc.h
index e1ee1eea..27c39e17 100644
--- a/bacnet-stack/include/bvlc.h
+++ b/bacnet-stack/include/bvlc.h
@@ -96,21 +96,21 @@ extern "C" {
 struct sockaddr_in;     /* Defined elsewhere, needed here. */
 
     /* Note any BVLC_RESULT code, or NAK the BVLL message in the unsupported cases. */
-    int bvlc_for_non_bbmd(     
-            struct sockaddr_in * sout,      
-            uint8_t * npdu,     
+    int bvlc_for_non_bbmd(
+            struct sockaddr_in * sout,
+            uint8_t * npdu,
             uint16_t received_bytes);
 
     /* Returns the last BVLL Result we received, either as the result of a BBMD
-     * request we sent, or (if not a BBMD or Client), from trying to register 
+     * request we sent, or (if not a BBMD or Client), from trying to register
      * as a foreign device. */
-    BACNET_BVLC_RESULT bvlc_get_last_result();
-    
+    BACNET_BVLC_RESULT bvlc_get_last_result(void);
+
     /* Returns the current BVLL Function Code we are processing.
      * We have to store this higher layer code for when the lower layers
      * need to know what it is, especially to differentiate between
      * BVLC_ORIGINAL_UNICAST_NPDU and BVLC_ORIGINAL_BROADCAST_NPDU.  */
-    BACNET_BVLC_FUNCTION bvlc_get_function_code();
+    BACNET_BVLC_FUNCTION bvlc_get_function_code(void);
 
 #ifdef __cplusplus
 }