diff --git a/imperative/python/test/unit/functional/test_functional.py b/imperative/python/test/unit/functional/test_functional.py
index 3401ad102bd2c15d8fb6b325b0e9afeb8745a7a2..4aec162711f6178661b58755a27b297312bfb134 100644
--- a/imperative/python/test/unit/functional/test_functional.py
+++ b/imperative/python/test/unit/functional/test_functional.py
@@ -11,6 +11,7 @@ import itertools
 import numpy as np
 import pytest
 
+import megengine.core.ops.builtin as builtin
 import megengine.core.tensor.dtype as dtype
 import megengine.functional as F
 from megengine import Buffer, Parameter, is_cuda_available, tensor
@@ -631,3 +632,20 @@ def test_condtake():
     val, idx = F.cond_take(yy, xx)
     np.testing.assert_equal(val.numpy(), x[y])
     np.testing.assert_equal(idx.numpy(), np.where(y.reshape(-1))[0])
+
+
+def test_condtake_is_same():
+    op1 = builtin.CondTake()
+    op2 = builtin.CondTake()
+    assert op1 == op2
+
+
+def test_nms_is_same():
+    op1 = builtin.NMSKeep(0.7, 100)
+    op2 = builtin.NMSKeep(0.7, 100)
+    op3 = builtin.NMSKeep(0.8, 100)
+    op4 = builtin.NMSKeep(0.7, 200)
+    assert op1 == op2
+    assert op1 != op3
+    assert op1 != op4
+    assert op3 != op4
diff --git a/imperative/src/include/megbrain/imperative/ops/cond_take.h b/imperative/src/include/megbrain/imperative/ops/cond_take.h
index 42a1c1a4892f6665adb56bf912f2da03fef13f3a..bed3465cecd016a2fb7bb3b9d991edbf1460a3a7 100644
--- a/imperative/src/include/megbrain/imperative/ops/cond_take.h
+++ b/imperative/src/include/megbrain/imperative/ops/cond_take.h
@@ -19,6 +19,15 @@ class CondTake : public OpDefImplBase<CondTake> {
     MGB_DYN_TYPE_OBJ_FINAL_DECL;
 public:
     CondTake() = default;
+
+    size_t hash() const override {
+        return reinterpret_cast<std::uintptr_t>(dyn_typeinfo());
+    }
+
+    bool is_same_st(const Hashable& rhs) const override {
+        return rhs.dyn_typeinfo() == dyn_typeinfo();
+    }
+
 };
 
 } // namespace mgb::imperative
diff --git a/imperative/src/include/megbrain/imperative/ops/nms.h b/imperative/src/include/megbrain/imperative/ops/nms.h
index 4e0c21ec0b29a93e11aa2d676025453ea5e20dd8..ad1bd96bec474373fd0bae92d5ac6aea2e0e214a 100644
--- a/imperative/src/include/megbrain/imperative/ops/nms.h
+++ b/imperative/src/include/megbrain/imperative/ops/nms.h
@@ -23,6 +23,20 @@ public:
     NMSKeep() = default;
     NMSKeep(float iou_thresh_, uint32_t max_output_):
         iou_thresh(iou_thresh_), max_output(max_output_) {}
+
+    size_t hash() const override {
+        return hash_pair_combine(
+                hash_pair_combine(mgb::hash(iou_thresh), mgb::hash(max_output)),
+                reinterpret_cast<std::uintptr_t>(dyn_typeinfo()));
+    }
+
+    bool is_same_st(const Hashable& rhs_) const override {
+        auto&& rhs = static_cast<const NMSKeep&>(rhs_);
+        return rhs.dyn_typeinfo() == dyn_typeinfo()
+            && rhs.iou_thresh == iou_thresh
+            && rhs.max_output == max_output;
+    }
+
 };
 
 } // namespace mgb::imperative