Until the user enters a 0, the program will keep asking for numbers. then compute the average of just the positive integers

In my program, it doesn't work if a user input a negative. It will still be included in the count.

#include <stdio.h>

int main() {
    double number, sum = 0;
    float average;
    int count;
    
    do {
        printf("Enter a number: ");
        scanf("%lf", &number);
        count++;
        if (number > 0)
            sum += number;
        average = sum / (count - 1);    
    } while (number != -1);

    printf("Average is %.1lf", average);

    return 0;
}