diff --git a/libsnark/zk_proof_systems/plonk/srs.hpp b/libsnark/zk_proof_systems/plonk/srs.hpp
index 2d28c6fe5..d87646a77 100644
--- a/libsnark/zk_proof_systems/plonk/srs.hpp
+++ b/libsnark/zk_proof_systems/plonk/srs.hpp
@@ -254,7 +254,7 @@ template<typename ppT> class transcript_hasher
 
 public:
     // constructor
-    transcript_hasher(std::vector<uint8_t> &buffer);
+    transcript_hasher();
 
     void add_element(const libff::Fr<ppT> &element);
     void add_element(const libff::G1<ppT> &element);
diff --git a/libsnark/zk_proof_systems/plonk/srs.tcc b/libsnark/zk_proof_systems/plonk/srs.tcc
index d52488575..5f5d33945 100644
--- a/libsnark/zk_proof_systems/plonk/srs.tcc
+++ b/libsnark/zk_proof_systems/plonk/srs.tcc
@@ -73,10 +73,10 @@ plonk_keypair<ppT>::plonk_keypair(
 }
 
 // transcript_hasher constructor
-template<typename ppT>
-transcript_hasher<ppT>::transcript_hasher(std::vector<uint8_t> &buffer)
-    : buffer(std::move(buffer))
+template<typename ppT> transcript_hasher<ppT>::transcript_hasher()
 {
+    // initialize to empty vector
+    this->buffer.clear();
     // test array containing the expected hash values of the communication
     // transcript i.e. the communication challenges (in this order): beta,
     // gamma, alpha, zeta, nu, u WARNING! specific to curve BLS12-381
diff --git a/libsnark/zk_proof_systems/plonk/tests/test_plonk.cpp b/libsnark/zk_proof_systems/plonk/tests/test_plonk.cpp
index 18cb18d36..2c82339dd 100644
--- a/libsnark/zk_proof_systems/plonk/tests/test_plonk.cpp
+++ b/libsnark/zk_proof_systems/plonk/tests/test_plonk.cpp
@@ -490,8 +490,7 @@ template<typename ppT> void test_plonk_prover_rounds()
     srs<ppT> srs = plonk_srs_derive_from_usrs<ppT>(usrs, circuit);
 
     // initialize hasher
-    std::vector<uint8_t> buffer;
-    transcript_hasher<ppT> hasher(buffer);
+    transcript_hasher<ppT> hasher;
 
     // Prover Round 0 (initialization)
     round_zero_out_t<ppT> round_zero_out = plonk_prover<ppT>::round_zero(srs);
@@ -692,8 +691,7 @@ template<typename ppT> void test_plonk_prover()
     srs<ppT> srs = plonk_srs_derive_from_usrs<ppT>(usrs, circuit);
 
     // initialize hasher
-    std::vector<uint8_t> buffer;
-    transcript_hasher<ppT> hasher(buffer);
+    transcript_hasher<ppT> hasher;
 
     // initialize prover
     plonk_prover<ppT> prover;
@@ -970,8 +968,7 @@ template<typename ppT> void test_plonk_verifier_steps()
     srs<ppT> srs = plonk_srs_derive_from_usrs<ppT>(usrs, circuit);
 
     // initialize hasher
-    std::vector<uint8_t> buffer;
-    transcript_hasher<ppT> hasher(buffer);
+    transcript_hasher<ppT> hasher;
 
     // initialize prover
     plonk_prover<ppT> prover;
@@ -1075,8 +1072,7 @@ template<typename ppT> void test_plonk_verifier()
     srs<ppT> srs = plonk_srs_derive_from_usrs<ppT>(usrs, circuit);
 
     // initialize hasher
-    std::vector<uint8_t> buffer;
-    transcript_hasher<ppT> hasher(buffer);
+    transcript_hasher<ppT> hasher;
 
     // initialize prover
     plonk_prover<ppT> prover;