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We present very long baseline interferometry (VLBI) observations of themilliarcsecond-scale radio structure of the supernova remnant SNR 4449$-$1 inthe galaxy NGC 4449. This young and superluminous remnant was observed at 1.6GHz ($\lambda = 18$\,cm) with the European VLBI Network. The observationsconfirm earlier identifications of this object with a supernova remnant (SNR)while revealing a somewhat different morphology compared with the structurereported by Bietenholz et al. from VLBI observations at 1.4 GHz. Thisdifference is discussed here in the context of structural sensitivity of bothobservations. The 1.6 GHz image yields accurate estimates of the size (0.0422arcsec $\times$ 0.0285 arcsec and 0.8 $\times$ 0.5 pc) and age ($\sim$55 yr) ofSNR 4449$-$1. With a total flux of 6.1 $\pm$ 0.6 mJy measured in the VLBIimage, the historical lightcurve of the source can be well represented by apower-law decay with a power index of $-$1.19 $\pm$ 0.07. The SNR exhibits adecline rate of the radio emission of 2.2$%$ $\pm$ 0.1$%$ yr$^{-1}$ and a radioluminosity of 1.74 $\times$ 10$^{35}$ erg s$^{-1}$.

The resolved structure of the extragalactic supernova remnant SNR 4449-1