diff --git a/src/p2pool.cpp b/src/p2pool.cpp
index dee34e2..4809d21 100644
--- a/src/p2pool.cpp
+++ b/src/p2pool.cpp
@@ -521,7 +521,7 @@ void p2pool::handle_chain_main(ChainMain& data, const char* extra)
 				LOGINFO(0, log::LightCyan() << "Your wallet " << log::LightYellow() << w << log::LightCyan() << " didn't get a payout in block " << log::LightYellow() << data.height << log::LightCyan() << " because you had no shares in PPLNS window");
 			}
 
-			api_update_block_found(&data, block);
+			api_update_block_found(&data, block, false);
 		}
 		else {
 			side_chain().watch_mainchain_block(data, merkle_root);
@@ -1680,7 +1680,7 @@ void p2pool::cleanup_mainchain_data(uint64_t height)
 	}
 }
 
-void p2pool::api_update_block_found(const ChainMain* data, const PoolBlock* block)
+void p2pool::api_update_block_found(const ChainMain* data, const PoolBlock* block, bool update_stats_mod)
 {
 	if (!m_api || m_stopped) {
 		return;
@@ -1727,7 +1727,9 @@ void p2pool::api_update_block_found(const ChainMain* data, const PoolBlock* bloc
 			s << ']';
 		});
 
-	api_update_stats_mod();
+	if (update_stats_mod) {
+		api_update_stats_mod();
+	}
 }
 
 bool p2pool::get_difficulty_at_height(uint64_t height, difficulty_type& diff)
diff --git a/src/p2pool.h b/src/p2pool.h
index 561d649..9ca01f3 100644
--- a/src/p2pool.h
+++ b/src/p2pool.h
@@ -110,7 +110,7 @@ public:
 
 	bool chainmain_get_by_hash(const hash& id, ChainMain& data) const;
 
-	void api_update_block_found(const ChainMain* data, const PoolBlock* block);
+	void api_update_block_found(const ChainMain* data, const PoolBlock* block, bool update_stats_mod = true);
 
 	bool get_difficulty_at_height(uint64_t height, difficulty_type& diff);
 
diff --git a/src/p2pool_api.cpp b/src/p2pool_api.cpp
index d62c01e..dc8b521 100644
--- a/src/p2pool_api.cpp
+++ b/src/p2pool_api.cpp
@@ -130,29 +130,36 @@ void p2pool_api::dump_to_file_async_internal(Category category, const char* file
 	}
 
 	MutexLock lock(m_dumpDataLock);
-	m_dumpData[path] = std::move(buf);
 
-	if (!uv_is_closing(reinterpret_cast<uv_handle_t*>(&m_dumpToFileAsync))) {
-		uv_async_send(&m_dumpToFileAsync);
+	std::pair<std::vector<char>, bool>& data = m_dumpData[path];
+
+	if (data.first != buf) {
+		data.first = buf;
+		data.second = true;
+
+		if (!uv_is_closing(reinterpret_cast<uv_handle_t*>(&m_dumpToFileAsync))) {
+			uv_async_send(&m_dumpToFileAsync);
+		}
 	}
 }
 
 void p2pool_api::dump_to_file()
 {
-	unordered_map<std::string, std::vector<char>> data;
-	{
-		MutexLock lock(m_dumpDataLock);
-		data = std::move(m_dumpData);
-	}
+	MutexLock lock(m_dumpDataLock);
 
 	char buf[log::Stream::BUF_SIZE + 1];
 	buf[0] = '\0';
 
-	for (auto& it : data) {
+	for (auto& it : m_dumpData) {
+		if (!it.second.second) {
+			continue;
+		}
+		it.second.second = false;
+
 		log::Stream s(buf);
 		s << it.first << m_counter << '\0';
 
-		DumpFileWork* work = new DumpFileWork{ {}, 0, it.first, buf, std::move(it.second) };
+		DumpFileWork* work = new DumpFileWork{ {}, 0, it.first, buf, it.second.first };
 		work->req.data = work;
 		++m_counter;
 
diff --git a/src/p2pool_api.h b/src/p2pool_api.h
index 2006e38..7655e9d 100644
--- a/src/p2pool_api.h
+++ b/src/p2pool_api.h
@@ -68,7 +68,7 @@ private:
 	std::string m_localPath;
 
 	uv_mutex_t m_dumpDataLock;
-	unordered_map<std::string, std::vector<char>> m_dumpData;
+	unordered_map<std::string, std::pair<std::vector<char>, bool>> m_dumpData;
 
 	uv_async_t m_dumpToFileAsync;