How to avoid line breaks in header tags?

I am using header tags and I don't want line break after them.

I tried using "display: inline;" property, but it didn't work.

My HTML code:

<h5>Token No.:</h5> <h4>147</h4>

My CSS code:

h5 {
    display: inline;
}

This should result in no line breaks, but it gives one after "Token no.:".