While migrating Elephant to numpy >= 2.0 we discovered the following bug, where in place basic operations +=, -=, /= and *= result in incorrect units.

Minimal example to reproduce:

a=5*pq.sb=6*pq.kga/=b# results incorrectly in a = 0.833 * sa=a/b# results in a = 0.833 * s/kg (expected)

With:

• Python 3.13.1
• quantities 0.16.1