diff --git a/deepmd/pt/model/descriptor/repformer_layer.py b/deepmd/pt/model/descriptor/repformer_layer.py
index 08fcb17b09..a58d6b0e2c 100644
--- a/deepmd/pt/model/descriptor/repformer_layer.py
+++ b/deepmd/pt/model/descriptor/repformer_layer.py
@@ -13,7 +13,7 @@
     env,
 )
 from deepmd.pt.utils.utils import (
-    get_activation_fn,
+    ActivationFn,
 )
 
 
@@ -332,7 +332,7 @@ def __init__(
         self.set_davg_zero = set_davg_zero
         self.do_bn_mode = do_bn_mode
         self.bn_momentum = bn_momentum
-        self.act = get_activation_fn(activation_function)
+        self.act = ActivationFn(activation_function)
         self.update_g1_has_grrg = update_g1_has_grrg
         self.update_g1_has_drrd = update_g1_has_drrd
         self.update_g1_has_conv = update_g1_has_conv
diff --git a/deepmd/pt/model/descriptor/repformers.py b/deepmd/pt/model/descriptor/repformers.py
index a908d2e057..16a38052b1 100644
--- a/deepmd/pt/model/descriptor/repformers.py
+++ b/deepmd/pt/model/descriptor/repformers.py
@@ -29,7 +29,7 @@
     PairExcludeMask,
 )
 from deepmd.pt.utils.utils import (
-    get_activation_fn,
+    ActivationFn,
 )
 from deepmd.utils.env_mat_stat import (
     StatItem,
@@ -117,7 +117,7 @@ def __init__(
         self.set_davg_zero = set_davg_zero
         self.g1_dim = g1_dim
         self.g2_dim = g2_dim
-        self.act = get_activation_fn(activation_function)
+        self.act = ActivationFn(activation_function)
         self.direct_dist = direct_dist
         self.add_type_ebd_to_seq = add_type_ebd_to_seq
         # order matters, placed after the assignment of self.ntypes
diff --git a/deepmd/pt/model/network/network.py b/deepmd/pt/model/network/network.py
index 10d0364c9b..60d5251994 100644
--- a/deepmd/pt/model/network/network.py
+++ b/deepmd/pt/model/network/network.py
@@ -27,7 +27,6 @@
 
 from deepmd.pt.utils.utils import (
     ActivationFn,
-    get_activation_fn,
 )
 
 
@@ -470,7 +469,7 @@ class MaskLMHead(nn.Module):
     def __init__(self, embed_dim, output_dim, activation_fn, weight=None):
         super().__init__()
         self.dense = SimpleLinear(embed_dim, embed_dim)
-        self.activation_fn = get_activation_fn(activation_fn)
+        self.activation_fn = ActivationFn(activation_fn)
         self.layer_norm = nn.LayerNorm(embed_dim, dtype=env.GLOBAL_PT_FLOAT_PRECISION)
 
         if weight is None:
@@ -818,7 +817,7 @@ def __init__(
             self.fc1 = nn.Linear(
                 self.embed_dim, self.ffn_embed_dim, dtype=env.GLOBAL_PT_FLOAT_PRECISION
             )
-            self.activation_fn = get_activation_fn(activation)
+            self.activation_fn = ActivationFn(activation)
             self.fc2 = nn.Linear(
                 self.ffn_embed_dim, self.embed_dim, dtype=env.GLOBAL_PT_FLOAT_PRECISION
             )
@@ -1387,7 +1386,7 @@ def __init__(
         self.ffn_dim = ffn_dim
         self.attn_head = attn_head
         self.activation_fn = (
-            get_activation_fn(activation_fn) if activation_fn is not None else None
+            ActivationFn(activation_fn) if activation_fn is not None else None
         )
         self.post_ln = post_ln
         self.self_attn_layer_norm = nn.LayerNorm(
diff --git a/deepmd/pt/utils/utils.py b/deepmd/pt/utils/utils.py
index 4b64a7231c..d1ef089e49 100644
--- a/deepmd/pt/utils/utils.py
+++ b/deepmd/pt/utils/utils.py
@@ -1,6 +1,5 @@
 # SPDX-License-Identifier: LGPL-3.0-or-later
 from typing import (
-    Callable,
     Optional,
     overload,
 )
@@ -18,26 +17,6 @@
 from .env import PRECISION_DICT as PT_PRECISION_DICT
 
 
-def get_activation_fn(activation: str) -> Callable:
-    """Returns the activation function corresponding to `activation`."""
-    if activation.lower() == "relu":
-        return F.relu
-    elif activation.lower() == "gelu" or activation.lower() == "gelu_tf":
-        return lambda x: F.gelu(x, approximate="tanh")
-    elif activation.lower() == "tanh":
-        return torch.tanh
-    elif activation.lower() == "relu6":
-        return F.relu6
-    elif activation.lower() == "softplus":
-        return F.softplus
-    elif activation.lower() == "sigmoid":
-        return torch.sigmoid
-    elif activation.lower() == "linear" or activation.lower() == "none":
-        return lambda x: x
-    else:
-        raise RuntimeError(f"activation function {activation} not supported")
-
-
 class ActivationFn(torch.nn.Module):
     def __init__(self, activation: Optional[str]):
         super().__init__()
diff --git a/source/tests/consistent/test_activation.py b/source/tests/consistent/test_activation.py
index 83b8494729..9dcac6746e 100644
--- a/source/tests/consistent/test_activation.py
+++ b/source/tests/consistent/test_activation.py
@@ -15,7 +15,7 @@
 )
 
 if INSTALLED_PT:
-    from deepmd.pt.utils.utils import get_activation_fn as get_activation_fn_pt
+    from deepmd.pt.utils.utils import ActivationFn as ActivationFn_pt
     from deepmd.pt.utils.utils import (
         to_numpy_array,
         to_torch_tensor,
@@ -49,8 +49,6 @@ def test_tf_consistent_with_ref(self):
     def test_pt_consistent_with_ref(self):
         if INSTALLED_PT:
             test = to_numpy_array(
-                get_activation_fn_pt(self.activation)(
-                    to_torch_tensor(self.random_input)
-                )
+                ActivationFn_pt(self.activation)(to_torch_tensor(self.random_input))
             )
             np.testing.assert_allclose(self.ref, test, atol=1e-10)