diff --git a/src/protocols/vnc/client.h b/src/protocols/vnc/client.h
index d7ac99c7..36f5870e 100644
--- a/src/protocols/vnc/client.h
+++ b/src/protocols/vnc/client.h
@@ -51,7 +51,7 @@
 /**
  * Handler which frees all data associated with the guac_client.
  */
-int guac_vnc_client_free_handler(guac_client* client);
+guac_client_free_handler guac_vnc_client_free_handler;
 
 #endif
 
diff --git a/src/protocols/vnc/clipboard.h b/src/protocols/vnc/clipboard.h
index 66a2372b..f6ee59eb 100644
--- a/src/protocols/vnc/clipboard.h
+++ b/src/protocols/vnc/clipboard.h
@@ -25,13 +25,9 @@
 
 #include "config.h"
 
-#include "guac_clipboard.h"
-
 #include <guacamole/client.h>
-#include <guacamole/stream.h>
 #include <guacamole/user.h>
 #include <rfb/rfbclient.h>
-#include <rfb/rfbproto.h>
 
 /**
  * Sets the encoding of clipboard data exchanged with the VNC server to the
@@ -55,17 +51,17 @@ int guac_vnc_set_clipboard_encoding(guac_client* client,
 /**
  * Handler for inbound clipboard data from Guacamole users.
  */
-int guac_vnc_clipboard_handler(guac_user* user, guac_stream* stream, char* mimetype);
+guac_user_clipboard_handler guac_vnc_clipboard_handler;
 
 /**
  * Handler for stream data related to clipboard.
  */
-int guac_vnc_clipboard_blob_handler(guac_user* user, guac_stream* stream, void* data, int length);
+guac_user_blob_handler guac_vnc_clipboard_blob_handler;
 
 /**
  * Handler for end-of-stream related to clipboard.
  */
-int guac_vnc_clipboard_end_handler(guac_user* user, guac_stream* stream);
+guac_user_end_handler guac_vnc_clipboard_end_handler;
 
 /**
  * Handler for clipboard data received via VNC.
diff --git a/src/protocols/vnc/input.h b/src/protocols/vnc/input.h
index d1923351..9205bd24 100644
--- a/src/protocols/vnc/input.h
+++ b/src/protocols/vnc/input.h
@@ -31,12 +31,12 @@
 /**
  * Handler for Guacamole user mouse events.
  */
-int guac_vnc_user_mouse_handler(guac_user* user, int x, int y, int mask);
+guac_user_mouse_handler guac_vnc_user_mouse_handler;
 
 /**
  * Handler for Guacamole user key events.
  */
-int guac_vnc_user_key_handler(guac_user* user, int keysym, int pressed);
+guac_user_key_handler guac_vnc_user_key_handler;
 
 #endif
 
diff --git a/src/protocols/vnc/sftp.h b/src/protocols/vnc/sftp.h
index 8c140b4e..816707cd 100644
--- a/src/protocols/vnc/sftp.h
+++ b/src/protocols/vnc/sftp.h
@@ -25,31 +25,13 @@
 
 #include "config.h"
 
-#include <guacamole/stream.h>
 #include <guacamole/user.h>
 
 /**
  * Handles an incoming stream from a Guacamole "file" instruction, saving the
  * contents of that stream to the file having the given name.
- *
- * @param user
- *     The user uploading the file.
- *
- * @param stream
- *     The stream through which the uploaded file data will be received.
- *
- * @param mimetype
- *     The mimetype of the data being received.
- *
- * @param filename
- *     The filename of the file to write to.
- *
- * @return
- *     Zero if the incoming stream has been handled successfully, non-zero on
- *     failure.
  */
-int guac_vnc_sftp_file_handler(guac_user* user, guac_stream* stream,
-        char* mimetype, char* filename);
+guac_user_file_handler guac_vnc_sftp_file_handler;
 
 #endif
 
diff --git a/src/protocols/vnc/user.h b/src/protocols/vnc/user.h
index c290bae1..d1cac984 100644
--- a/src/protocols/vnc/user.h
+++ b/src/protocols/vnc/user.h
@@ -25,19 +25,17 @@
 
 #include "config.h"
 
-#include "guac_clipboard.h"
-
 #include <guacamole/user.h>
 
 /**
  * Handler for joining users.
  */
-int guac_vnc_user_join_handler(guac_user* user, int argc, char** argv);
+guac_user_join_handler guac_vnc_user_join_handler;
 
 /**
  * Handler for leaving users.
  */
-int guac_vnc_user_leave_handler(guac_user* user);
+guac_user_leave_handler guac_vnc_user_leave_handler;
 
 #endif