Article 25 of the 1848 Constitution of the Grand Duchy of Luxembourg grants freedom of expression along with freedom of the press to Luxembourgers “except for the repression of the offenses committed on the occasion of the exercise of these freedoms.” This is continued in Luxembourg’s 1868 Constitution.

References:

Constitution of the Grand Duchy of Luxembourg, 1848. HeinOnline (2013), World Constitutions Illustrated, HeinOnline: https://heinonline.org/HOL/COWShow?collection=cow&cow_id=244

Constitution of the Grand Duchy of Luxembourg, 1868. H.F. Wright (2019), World Constitutions Illustrated, HeinOnline: https://heinonline.org/HOL/P?h=hein.cow/zzlu0013&i=1