diff --git a/metatomic-torch/src/model.cpp b/metatomic-torch/src/model.cpp
index 7bc7e347..dac2b65a 100644
--- a/metatomic-torch/src/model.cpp
+++ b/metatomic-torch/src/model.cpp
@@ -1141,6 +1141,7 @@ static std::map<std::string, Quantity> KNOWN_QUANTITIES = {
         {"A/fs", 1e1},
         {"m/s", 1e6},
         {"nm/ps", 1e3},
+        {"(eV/u)^(1/2)", 101.80506},
     }, {
         // alternative names
     }}},
diff --git a/python/metatomic_torch/metatomic/torch/ase_calculator.py b/python/metatomic_torch/metatomic/torch/ase_calculator.py
index 84e5d4d9..76964aaa 100644
--- a/python/metatomic_torch/metatomic/torch/ase_calculator.py
+++ b/python/metatomic_torch/metatomic/torch/ase_calculator.py
@@ -65,7 +65,7 @@ def _get_charges(atoms: ase.Atoms) -> np.ndarray:
     "velocities": {
         "quantity": "velocity",
         "getter": ase.Atoms.get_velocities,
-        "unit": "nm/fs",
+        "unit": "(eV/u)^(1/2)",
     },
     "charges": {
         "quantity": "charge",
diff --git a/python/metatomic_torch/tests/ase_calculator.py b/python/metatomic_torch/tests/ase_calculator.py
index f0ae7be7..a1d1e57f 100644
--- a/python/metatomic_torch/tests/ase_calculator.py
+++ b/python/metatomic_torch/tests/ase_calculator.py
@@ -866,6 +866,8 @@ def test_additional_input(atoms):
 
         expected = ARRAY_QUANTITIES[name]["getter"](atoms).reshape(values.shape)
         if name == "velocities":
-            expected *= 10.0  # ase velocity is in nm/fs
+            expected /= (
+                ase.units.Angstrom / ase.units.fs
+            )  # ase velocity is in (eV/u)^(1/2) and we want A/fs
 
         assert np.allclose(values, expected)