C Struct - field has incomplete type

Question

In my header file I have this

    typedef struct _client_value
{
    int client_id;
    struct timeval t;
    size_t size;
    char value[0];
} client_value;

I already included <time.h> but when I compiled, it said: field 't' has incomplete type struct timeval t.

I don't understand how this could happen.

Answer 1

Its #include <sys/time.h>