diff -rup a/include/mysql/client_plugin.h b/include/mysql/client_plugin.h
--- a/include/mysql/client_plugin.h	2016-05-25 07:50:36.000000000 +0200
+++ b/include/mysql/client_plugin.h	2016-06-03 13:02:20.340353732 +0200
@@ -89,7 +89,7 @@ extern "C" {
   const char *license;                                  \
   void *mysql_api;                                      \
   int (*init)(char *, size_t, int, va_list);            \
-  int (*deinit)();                                      \
+  int (*deinit)(void);                                  \
   int (*options)(const char *option, const void *);
 
 struct st_mysql_client_plugin
diff -rup a/include/mysql/client_plugin.h.pp b/include/mysql/client_plugin.h.pp
--- a/include/mysql/client_plugin.h.pp	2016-05-25 07:50:36.000000000 +0200
+++ b/include/mysql/client_plugin.h.pp	2016-06-03 13:02:20.340353732 +0200
@@ -1,6 +1,6 @@
 struct st_mysql_client_plugin
 {
-  int type; unsigned int interface_version; const char *name; const char *author; const char *desc; unsigned int version[3]; const char *license; void *mysql_api; int (*init)(char *, size_t, int, va_list); int (*deinit)(); int (*options)(const char *option, const void *);
+  int type; unsigned int interface_version; const char *name; const char *author; const char *desc; unsigned int version[3]; const char *license; void *mysql_api; int (*init)(char *, size_t, int, va_list); int (*deinit)(void); int (*options)(const char *option, const void *);
 };
 struct st_mysql;
 #include "plugin_auth_common.h"
@@ -21,7 +21,7 @@ typedef struct st_plugin_vio
 } MYSQL_PLUGIN_VIO;
 struct st_mysql_client_plugin_AUTHENTICATION
 {
-  int type; unsigned int interface_version; const char *name; const char *author; const char *desc; unsigned int version[3]; const char *license; void *mysql_api; int (*init)(char *, size_t, int, va_list); int (*deinit)(); int (*options)(const char *option, const void *);
+  int type; unsigned int interface_version; const char *name; const char *author; const char *desc; unsigned int version[3]; const char *license; void *mysql_api; int (*init)(char *, size_t, int, va_list); int (*deinit)(void); int (*options)(const char *option, const void *);
   int (*authenticate_user)(MYSQL_PLUGIN_VIO *vio, struct st_mysql *mysql);
 };
 struct st_mysql_client_plugin *
diff -rup a/include/mysql.h.pp b/include/mysql.h.pp
--- a/include/mysql.h.pp	2016-05-25 07:50:36.000000000 +0200
+++ b/include/mysql.h.pp	2016-06-03 13:02:20.340353732 +0200
@@ -213,7 +213,7 @@ extern int list_walk(LIST *,list_walk_ac
 #include "mysql/client_plugin.h"
 struct st_mysql_client_plugin
 {
-  int type; unsigned int interface_version; const char *name; const char *author; const char *desc; unsigned int version[3]; const char *license; void *mysql_api; int (*init)(char *, size_t, int, va_list); int (*deinit)(); int (*options)(const char *option, const void *);
+  int type; unsigned int interface_version; const char *name; const char *author; const char *desc; unsigned int version[3]; const char *license; void *mysql_api; int (*init)(char *, size_t, int, va_list); int (*deinit)(void); int (*options)(const char *option, const void *);
 };
 struct st_mysql;
 #include "plugin_auth_common.h"
@@ -234,7 +234,7 @@ typedef struct st_plugin_vio
 } MYSQL_PLUGIN_VIO;
 struct st_mysql_client_plugin_AUTHENTICATION
 {
-  int type; unsigned int interface_version; const char *name; const char *author; const char *desc; unsigned int version[3]; const char *license; void *mysql_api; int (*init)(char *, size_t, int, va_list); int (*deinit)(); int (*options)(const char *option, const void *);
+  int type; unsigned int interface_version; const char *name; const char *author; const char *desc; unsigned int version[3]; const char *license; void *mysql_api; int (*init)(char *, size_t, int, va_list); int (*deinit)(void); int (*options)(const char *option, const void *);
   int (*authenticate_user)(MYSQL_PLUGIN_VIO *vio, struct st_mysql *mysql);
 };
 struct st_mysql_client_plugin *