diff --git a/libraries/chain/controller.cpp b/libraries/chain/controller.cpp
index 71b99a59a5..4e9c1439bc 100644
--- a/libraries/chain/controller.cpp
+++ b/libraries/chain/controller.cpp
@@ -483,7 +483,6 @@ struct controller_impl {
       }
 
       auto blog_head = blog.head();
-      auto blog_head_time = blog_head ? blog_head->timestamp.to_time_point() : fork_db.root()->header.timestamp.to_time_point();
       replaying = true;
       auto start_block_num = head->block_num + 1;
       auto start = fc::time_point::now();
@@ -821,7 +820,10 @@ struct controller_impl {
       });
    }
 
-   void add_to_snapshot( const snapshot_writer_ptr& snapshot ) const {
+   void add_to_snapshot( const snapshot_writer_ptr& snapshot ) {
+      // clear in case the previous call to clear did not finish in time of deadline
+      clear_expired_input_transactions( fc::time_point::maximum() );
+
       snapshot->write_section<chain_snapshot_header>([this]( auto &section ){
          section.add_row(chain_snapshot_header(), db);
       });
@@ -994,7 +996,7 @@ struct controller_impl {
       );
    }
 
-   sha256 calculate_integrity_hash() const {
+   sha256 calculate_integrity_hash() {
       sha256::encoder enc;
       auto hash_writer = std::make_shared<integrity_hash_snapshot_writer>(enc);
       add_to_snapshot(hash_writer);
@@ -2420,7 +2422,7 @@ struct controller_impl {
       //Look for expired transactions in the deduplication list, and remove them.
       auto& transaction_idx = db.get_mutable_index<transaction_multi_index>();
       const auto& dedupe_index = transaction_idx.indices().get<by_expiration>();
-      auto now = self.pending_block_time();
+      auto now = self.is_building_block() ? self.pending_block_time() : self.head_block_time();
       const auto total = dedupe_index.size();
       uint32_t num_removed = 0;
       while( (!dedupe_index.empty()) && ( now > fc::time_point(dedupe_index.begin()->expiration) ) ) {
@@ -3132,11 +3134,11 @@ block_id_type controller::get_block_id_for_num( uint32_t block_num )const { try
    return id;
 } FC_CAPTURE_AND_RETHROW( (block_num) ) }
 
-sha256 controller::calculate_integrity_hash()const { try {
+sha256 controller::calculate_integrity_hash() { try {
    return my->calculate_integrity_hash();
 } FC_LOG_AND_RETHROW() }
 
-void controller::write_snapshot( const snapshot_writer_ptr& snapshot ) const {
+void controller::write_snapshot( const snapshot_writer_ptr& snapshot ) {
    EOS_ASSERT( !my->pending, block_validate_exception, "cannot take a consistent snapshot with a pending block" );
    return my->add_to_snapshot(snapshot);
 }
diff --git a/libraries/chain/include/eosio/chain/controller.hpp b/libraries/chain/include/eosio/chain/controller.hpp
index e49e1e9fa5..da6fe4c4d1 100644
--- a/libraries/chain/include/eosio/chain/controller.hpp
+++ b/libraries/chain/include/eosio/chain/controller.hpp
@@ -257,8 +257,8 @@ namespace eosio { namespace chain {
 
          block_id_type get_block_id_for_num( uint32_t block_num )const;
 
-         sha256 calculate_integrity_hash()const;
-         void write_snapshot( const snapshot_writer_ptr& snapshot )const;
+         sha256 calculate_integrity_hash();
+         void write_snapshot( const snapshot_writer_ptr& snapshot );
 
          bool sender_avoids_whitelist_blacklist_enforcement( account_name sender )const;
          void check_actor_list( const flat_set<account_name>& actors )const;
diff --git a/unittests/snapshot_tests.cpp b/unittests/snapshot_tests.cpp
index 5abe4e5305..9365e90a31 100644
--- a/unittests/snapshot_tests.cpp
+++ b/unittests/snapshot_tests.cpp
@@ -159,7 +159,7 @@ namespace {
    }
 
    template <typename SNAPSHOT_SUITE>
-   void verify_integrity_hash(const controller& lhs, const controller& rhs) {
+   void verify_integrity_hash(controller& lhs, controller& rhs) {
       const auto lhs_integrity_hash = lhs.calculate_integrity_hash();
       const auto rhs_integrity_hash = rhs.calculate_integrity_hash();
       if (std::is_same_v<SNAPSHOT_SUITE, variant_snapshot_suite> && lhs_integrity_hash.str() != rhs_integrity_hash.str()) {