diff --git a/CHANGES.md b/CHANGES.md
index efa43a9d9..7de01b1bf 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -2,6 +2,10 @@
 
 ## Version 3.5.0
 
+### Hotfix - 4/30/2020
+
+- Fixed a critical bug [(Issue 166)](https://github.com/microsoft/SEAL/issues/166) in `Evaluator::multiply_plain_inplace`. Thanks s0l0ist!
+
 ### Hotfix - 4/29/2020
 
 - Switched to using Microsoft GSL v3.0.1 and fixed minor GSL related issues in `CMakeLists.txt`.
diff --git a/native/tests/seal/evaluator.cpp b/native/tests/seal/evaluator.cpp
index a5f291877..4e1202c3e 100644
--- a/native/tests/seal/evaluator.cpp
+++ b/native/tests/seal/evaluator.cpp
@@ -991,6 +991,76 @@ namespace sealtest
             ASSERT_EQ(static_cast<uint64_t>(0x5B05B058), encoder.decode_uint64(plain));
             ASSERT_TRUE(encrypted.parms_id() == context->first_parms_id());
         }
+        {
+            EncryptionParameters parms(scheme_type::BFV);
+            Modulus plain_modulus(PlainModulus::Batching(64, 20));
+            parms.set_poly_modulus_degree(64);
+            parms.set_plain_modulus(plain_modulus);
+            parms.set_coeff_modulus(CoeffModulus::Create(64, { 30, 30, 30 }));
+
+            auto context = SEALContext::Create(parms, false, sec_level_type::none);
+            KeyGenerator keygen(context);
+
+            BatchEncoder batch_encoder(context);
+            Encryptor encryptor(context, keygen.public_key());
+            Evaluator evaluator(context);
+            Decryptor decryptor(context, keygen.secret_key());
+
+            Ciphertext encrypted;
+            Plaintext plain;
+            vector<int64_t> result;
+
+            batch_encoder.encode(vector<int64_t>(batch_encoder.slot_count(), 7), plain);
+            encryptor.encrypt(plain, encrypted);
+            evaluator.multiply_plain_inplace(encrypted, plain);
+            decryptor.decrypt(encrypted, plain);
+            batch_encoder.decode(plain, result);
+            ASSERT_TRUE(vector<int64_t>(batch_encoder.slot_count(), 49) == result);
+            ASSERT_TRUE(encrypted.parms_id() == context->first_parms_id());
+
+            batch_encoder.encode(vector<int64_t>(batch_encoder.slot_count(), -7), plain);
+            encryptor.encrypt(plain, encrypted);
+            evaluator.multiply_plain_inplace(encrypted, plain);
+            decryptor.decrypt(encrypted, plain);
+            batch_encoder.decode(plain, result);
+            ASSERT_TRUE(vector<int64_t>(batch_encoder.slot_count(), 49) == result);
+            ASSERT_TRUE(encrypted.parms_id() == context->first_parms_id());
+        }
+        {
+            EncryptionParameters parms(scheme_type::BFV);
+            Modulus plain_modulus(PlainModulus::Batching(64, 40));
+            parms.set_poly_modulus_degree(64);
+            parms.set_plain_modulus(plain_modulus);
+            parms.set_coeff_modulus(CoeffModulus::Create(64, { 30, 30, 30 }));
+
+            auto context = SEALContext::Create(parms, false, sec_level_type::none);
+            KeyGenerator keygen(context);
+
+            BatchEncoder batch_encoder(context);
+            Encryptor encryptor(context, keygen.public_key());
+            Evaluator evaluator(context);
+            Decryptor decryptor(context, keygen.secret_key());
+
+            Ciphertext encrypted;
+            Plaintext plain;
+            vector<int64_t> result;
+
+            batch_encoder.encode(vector<int64_t>(batch_encoder.slot_count(), 7), plain);
+            encryptor.encrypt(plain, encrypted);
+            evaluator.multiply_plain_inplace(encrypted, plain);
+            decryptor.decrypt(encrypted, plain);
+            batch_encoder.decode(plain, result);
+            ASSERT_TRUE(vector<int64_t>(batch_encoder.slot_count(), 49) == result);
+            ASSERT_TRUE(encrypted.parms_id() == context->first_parms_id());
+
+            batch_encoder.encode(vector<int64_t>(batch_encoder.slot_count(), -7), plain);
+            encryptor.encrypt(plain, encrypted);
+            evaluator.multiply_plain_inplace(encrypted, plain);
+            decryptor.decrypt(encrypted, plain);
+            batch_encoder.decode(plain, result);
+            ASSERT_TRUE(vector<int64_t>(batch_encoder.slot_count(), 49) == result);
+            ASSERT_TRUE(encrypted.parms_id() == context->first_parms_id());
+        }
     }
 
     TEST(EvaluatorTest, BFVEncryptMultiplyDecrypt)