System comprising a first furniture part (100; 100'), a second furniture part (200; 200') and a locking arrangement, the first furniture part (100; 100') comprising a recess (101; 101') having a depth and having, transversely to the depth, an oblong shape and an insertion portion (102; 102') and a locking portion (103; 103'), wherein the locking portion (103; 103') along an inner wall thereof comprises a groove (104; 104') the second furniture part (200; 200') comprising a wall portion having an extension along a longitudinal direction, and the locking arrangement comprising: a protrusion (400; 400') forming part of or being attachable to the second furniture part (200; 200'), and having an extension along the longitudinal direction towards a free end of the protrusion (400; 400'), and comprising a rim (401; 401') extending transverse the longitudinal direction and along at least a part of the protrusion's (400; 400') circumference; and a locking plug (300; 300') configured to be lockingly inserted into the insertion portion (102: 102') in a condition when the protrusion (400; 400') has been inserted into the insertion portion (102; 102') and has been transferred to the locking portion (103; 103'), wherein the locking plug (300; 300') at least partly occupies the insertion portion (102; 102') and thereby counteracts transferring of the protrusion (400; 400') towards the insertion portion (102; 102'), and wherein the locking plug (300; 300') comprises a friction surface (303: 303') extending along the longitudinal direction, said friction surface (303; 303') being configured to lockingly or wedgingly abut a guiding surface (402; 402') of the protrusion (400; 400') in a condition when the locking plug (300; 300') has been inserted into the insertion portion (102; 102'). the first furniture part (100; 100') comprising a recess (101; 101') having a depth and having, transversely to the depth, an oblong shape and an insertion portion (102; 102') and a locking portion (103; 103'), wherein the locking portion (103; 103') along an inner wall thereof comprises a groove (104; 104') the second furniture part (200; 200') comprising a wall portion having an extension along a longitudinal direction, and the locking arrangement comprising: a protrusion (400; 400') forming part of or being attachable to the second furniture part (200; 200'), and having an extension along the longitudinal direction towards a free end of the protrusion (400; 400'), and comprising a rim (401; 401') extending transverse the longitudinal direction and along at least a part of the protrusion's (400; 400') circumference; and a locking plug (300; 300') configured to be lockingly inserted into the insertion portion (102: 102') in a condition when the protrusion (400; 400') has been inserted into the insertion portion (102; 102') and has been transferred to the locking portion (103; 103'), wherein the locking plug (300; 300') at least partly occupies the insertion portion (102; 102') and thereby counteracts transferring of the protrusion (400; 400') towards the insertion portion (102; 102'), and wherein the locking plug (300; 300') comprises a friction surface (303: 303') extending along the longitudinal direction, said friction surface (303; 303') being configured to lockingly or wedgingly abut a guiding surface (402; 402') of the protrusion (400; 400') in a condition when the locking plug (300; 300') has been inserted into the insertion portion (102; 102'). a protrusion (400; 400') forming part of or being attachable to the second furniture part (200; 200'), and having an extension along the longitudinal direction towards a free end of the protrusion (400; 400'), and comprising a rim (401; 401') extending transverse the longitudinal direction and along at least a part of the protrusion's (400; 400') circumference; and a locking plug (300; 300') configured to be lockingly inserted into the insertion portion (102: 102') in a condition when the protrusion (400; 400') has been inserted into the insertion portion (102; 102') and has been transferred to the locking portion (103; 103'), wherein the locking plug (300; 300') at least partly occupies the insertion portion (102; 102') and thereby counteracts transferring of the protrusion (400; 400') towards the insertion portion (102; 102'), and wherein the locking plug (300; 300') comprises a friction surface (303: 303') extending along the longitudinal direction, said friction surface (303; 303') being configured to lockingly or wedgingly abut a guiding surface (402; 402') of the protrusion (400; 400') in a condition when the locking plug (300; 300') has been inserted into the insertion portion (102; 102').