I cannot reproduce this issue locally using your code and 1.1.0 vs.1.5.0 (and even see a speedup in 1.5.0):
# 1.1.0
0.037771
0.028694
0.0278
0.027791
0.027526
0.027028
0.026608
0.026616
0.026561
0.026622
AVG: 0.028301699999999996

# 1.5.0
0.049427
0.023679
0.022723
0.022489
0.02304
0.022363
0.022008
0.022061
0.022063
0.022719
AVG: 0.025257199999999997