diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 9bde839c..3f07ede8 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -14,7 +14,8 @@ set(SPDLOG_UTESTS_SOURCES
     test_mpmc_q.cpp
     test_sink.h
     test_fmt_helper.cpp
-	test_stdout_api.cpp)
+	test_stdout_api.cpp
+    test_dup_filter.cpp)
 
 file(MAKE_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/logs")
 enable_testing()
diff --git a/tests/test_dup_filter.cpp b/tests/test_dup_filter.cpp
new file mode 100644
index 00000000..8ee9d832
--- /dev/null
+++ b/tests/test_dup_filter.cpp
@@ -0,0 +1,77 @@
+#include "includes.h"
+#include "spdlog/sinks/dup_filter_sink.h"
+#include "test_sink.h"
+
+using namespace spdlog;
+using namespace spdlog::sinks;
+
+
+TEST_CASE("dup_filter_test1", "[dup_filter_sink]")
+{
+    dup_filter_sink_st dup_sink {std::chrono::seconds{5}};
+    auto test_sink = std::make_shared<test_sink_mt>();
+    dup_sink.add_sink(test_sink);
+
+    for(int i = 0; i < 10; i++)
+    {
+        dup_sink.log(spdlog::details::log_msg{"test", spdlog::level::info, "message1"});
+    }
+
+    REQUIRE(test_sink->msg_counter() == 1);
+}
+
+TEST_CASE("dup_filter_test2", "[dup_filter_sink]")
+{
+    dup_filter_sink_st dup_sink {std::chrono::seconds{0}};
+    auto test_sink = std::make_shared<test_sink_mt>();
+    dup_sink.add_sink(test_sink);
+
+    for(int i = 0; i < 10; i++)
+    {
+        dup_sink.log(spdlog::details::log_msg{"test", spdlog::level::info, "message1"});
+    }
+
+    REQUIRE(test_sink->msg_counter() == 10);
+}
+
+TEST_CASE("dup_filter_test3", "[dup_filter_sink]")
+{
+    dup_filter_sink_st dup_sink {std::chrono::seconds{0}};
+    auto test_sink = std::make_shared<test_sink_mt>();
+    dup_sink.add_sink(test_sink);
+
+    for(int i = 0; i < 10; i++)
+    {
+        dup_sink.log(spdlog::details::log_msg{"test", spdlog::level::info, "message1"});
+        dup_sink.log(spdlog::details::log_msg{"test", spdlog::level::info, "message2"});
+    }
+
+    REQUIRE(test_sink->msg_counter() == 20);
+}
+
+TEST_CASE("dup_filter_test4", "[dup_filter_sink]")
+{
+    dup_filter_sink_st dup_sink {std::chrono::milliseconds{10}};
+    auto test_sink = std::make_shared<test_sink_mt>();
+    dup_sink.add_sink(test_sink);
+
+    dup_sink.log(spdlog::details::log_msg{"test", spdlog::level::info, "message"});
+    std::this_thread::sleep_for(std::chrono::milliseconds(50));
+    dup_sink.log(spdlog::details::log_msg{"test", spdlog::level::info, "message"});
+    REQUIRE(test_sink->msg_counter() == 2);
+}
+
+TEST_CASE("dup_filter_test5", "[dup_filter_sink]")
+{
+    dup_filter_sink_st dup_sink {std::chrono::seconds{5}};
+    auto test_sink = std::make_shared<test_sink_mt>();
+    dup_sink.add_sink(test_sink);
+
+    dup_sink.log(spdlog::details::log_msg{"test", spdlog::level::info, "message1"});
+    dup_sink.log(spdlog::details::log_msg{"test", spdlog::level::info, "message1"});
+    dup_sink.log(spdlog::details::log_msg{"test", spdlog::level::info, "message1"});
+    dup_sink.log(spdlog::details::log_msg{"test", spdlog::level::info, "message2"});
+
+    REQUIRE(test_sink->msg_counter() == 3); // skip 2 messages but log the "skipped.." message before message2
+}
+