We present the results of a study of time-delays in the photoionization of argon atoms in the combined presence of an IR laser field and of an attosecond pulse train of XUV harmonics (RABBIT set-up). The frequency of the pump laser was tuned with objective to make one of the harmonics to scan a Fano resonance involving the 3s²3p⁶ → 3s¹3p⁶4p¹ transition. The experimental results are modeled with the help of a theoretical treatment that accounts for the variations of the time-delays in the region close to the resonance.