diff --git a/include/ma_cio.h b/include/ma_cio.h
index 6000e823..0c2e17b8 100644
--- a/include/ma_cio.h
+++ b/include/ma_cio.h
@@ -116,5 +116,6 @@ my_bool ma_cio_is_blocking(MARIADB_CIO *cio);
 int ma_cio_wait_io_or_timeout(MARIADB_CIO *cio, my_bool is_read, int timeout);
 my_bool ma_cio_connect(MARIADB_CIO *cio, MA_CIO_CINFO *cinfo);
 my_bool ma_cio_is_alive(MARIADB_CIO *cio);
+my_bool ma_cio_get_handle(MARIADB_CIO *cio, void *handle);
 
 #endif /* _ma_cio_h_ */
diff --git a/libmariadb/get_password.c b/libmariadb/get_password.c
index a00387a3..fb78da9c 100644
--- a/libmariadb/get_password.c
+++ b/libmariadb/get_password.c
@@ -117,7 +117,6 @@ char* get_tty_password(char *prompt, char *buffer, int length)
   HANDLE Hdl;
   int    Offset= 0;
   DWORD  CharsProcessed=  0;
-  char   inChar;
 
   if (prompt)
     fprintf(stderr, "%s", prompt);
diff --git a/libmariadb/ma_cio.c b/libmariadb/ma_cio.c
index e9244fca..55c94c98 100644
--- a/libmariadb/ma_cio.c
+++ b/libmariadb/ma_cio.c
@@ -133,6 +133,7 @@ my_bool ma_cio_is_alive(MARIADB_CIO *cio)
 {
   if (cio->methods->is_alive)
     return cio->methods->is_alive(cio);
+  return FALSE;
 }
 /* }}} */
 
diff --git a/plugins/cio/cio_socket.c b/plugins/cio/cio_socket.c
index 509545ea..19b6d545 100644
--- a/plugins/cio/cio_socket.c
+++ b/plugins/cio/cio_socket.c
@@ -314,7 +314,7 @@ size_t cio_socket_async_read(MARIADB_CIO *cio, const uchar *buffer, size_t lengt
 #ifndef _WIN32
   r= recv(csock->socket,(void *)buffer, length, read_flags);
 #else
-  r= recv(csock->socket, buffer, length, 0);
+  r= recv(csock->socket, (char *)buffer, length, 0);
 #endif
   return r;
 }
diff --git a/plugins/connection/replication.c b/plugins/connection/replication.c
index 7a21bf1e..c32f67f6 100644
--- a/plugins/connection/replication.c
+++ b/plugins/connection/replication.c
@@ -245,7 +245,7 @@ void repl_close(MYSQL *mysql)
   my_free(data->url);
   my_free(data);
   mysql->net.conn_hdlr->data= NULL;
-  return mysql_close(mysql);
+  mysql_close(mysql);
 }
 
 static my_bool is_slave_command(const char *buffer, size_t buffer_len)
diff --git a/plugins/trace/trace_example.c b/plugins/trace/trace_example.c
index a8fc75ef..a998c929 100644
--- a/plugins/trace/trace_example.c
+++ b/plugins/trace/trace_example.c
@@ -216,6 +216,7 @@ static int trace_deinit()
     trace_info= trace_info->next;
   }
   register_callback(FALSE, trace_callback);
+  return 0;
 }
 
 static void trace_set_command(TRACE_INFO *info, char *buffer, size_t size)
@@ -250,7 +251,7 @@ static void dump_reference(TRACE_INFO *info, my_bool is_error)
 
 static void dump_command(TRACE_INFO *info, my_bool is_error)
 {
-  int i;
+  size_t i;
   printf("%8d: %s(",  info->thread_id, commands[info->last_command]);
   for (i= 0; info->command && i < strlen(info->command); i++)
     if (info->command[i] == '\n')
diff --git a/unittest/libmariadb/async.c b/unittest/libmariadb/async.c
index e54fb74d..2594b726 100644
--- a/unittest/libmariadb/async.c
+++ b/unittest/libmariadb/async.c
@@ -204,6 +204,7 @@ static int test_conc129(MYSQL *my)
 {
   MYSQL *mysql= mysql_init(NULL);
   FAIL_IF(mysql_close_start(mysql), "No error expected");
+  return OK;
 }
 
 
diff --git a/unittest/libmariadb/misc.c b/unittest/libmariadb/misc.c
index a5df2bc0..abacf6c5 100644
--- a/unittest/libmariadb/misc.c
+++ b/unittest/libmariadb/misc.c
@@ -802,7 +802,7 @@ static int test_conc49(MYSQL *mysql)
   rc= mysql_query(mysql, "SELECT a FROM conc49");
   check_mysql_rc(rc, mysql);
   res= mysql_store_result(mysql);
-  rc= mysql_num_rows(res);
+  rc= (int)mysql_num_rows(res);
   mysql_free_result(res);
   FAIL_IF(rc != 3, "3 rows expected");
   return OK;
@@ -922,7 +922,7 @@ static int test_connect_attrs(MYSQL *my)
   rc= mysql_query(mysql, "SELECT * FROM performance_schema.session_connect_attrs where attr_name like 'foo%'");
   check_mysql_rc(rc, mysql);
   result= mysql_store_result(mysql);
-  rc= mysql_num_rows(result);
+  rc= (int)mysql_num_rows(result);
   mysql_free_result(result);
 
   mysql_options(mysql, MYSQL_OPT_CONNECT_ATTR_RESET, NULL);