diff --git a/.travis.yml b/.travis.yml
index c80ef67d..50a6ba31 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -36,6 +36,6 @@ matrix:
         - CMAKE_PATH="/c/Program Files/CMake/bin"
       script: 
         - export PATH=$CMAKE_PATH:$PATH
-        - cmake -DUSE_TLS=1 -DUSE_WS=1 -DUSE_MBED_TLS=1 .
+        - cmake -DUSE_TLS=1 -DUSE_WS=1 -DUSE_MBED_TLS=1 -DUSE_VENDORED_THIRD_PARTY=1 .
         - cmake --build --parallel .
         - python test/run.py
diff --git a/CHANGELOG.md b/CHANGELOG.md
index fd40f76e..e848e5b8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,7 @@ All notable changes to this project will be documented in this file.
 
 ## [unreleased] - 2019-06-09
 ### Changed
+- mbedtls and zlib are searched with find_package, and we use the vendored version if nothing is found
 - travis CI uses g++ on Linux
 
 ## [4.0.0] - 2019-06-09
diff --git a/CMake/FindMbedTLS.cmake b/CMake/FindMbedTLS.cmake
new file mode 100644
index 00000000..a9163958
--- /dev/null
+++ b/CMake/FindMbedTLS.cmake
@@ -0,0 +1,13 @@
+find_path(MBEDTLS_INCLUDE_DIRS mbedtls/ssl.h)
+
+find_library(MBEDTLS_LIBRARY mbedtls)
+find_library(MBEDX509_LIBRARY mbedx509)
+find_library(MBEDCRYPTO_LIBRARY mbedcrypto)
+
+set(MBEDTLS_LIBRARIES "${MBEDTLS_LIBRARY}" "${MBEDX509_LIBRARY}" "${MBEDCRYPTO_LIBRARY}")
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(MBEDTLS DEFAULT_MSG
+    MBEDTLS_INCLUDE_DIRS MBEDTLS_LIBRARY MBEDX509_LIBRARY MBEDCRYPTO_LIBRARY)
+
+mark_as_advanced(MBEDTLS_INCLUDE_DIRS MBEDTLS_LIBRARY MBEDX509_LIBRARY MBEDCRYPTO_LIBRARY)
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 18d334de..9db0d402 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -4,6 +4,8 @@
 #
 
 cmake_minimum_required(VERSION 3.4.1)
+set(CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/CMake;${CMAKE_MODULE_PATH}")
+
 project(ixwebsocket C CXX)
 
 set (CMAKE_CXX_STANDARD 14)
@@ -20,64 +22,64 @@ if ("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang")
 endif()
 
 set( IXWEBSOCKET_SOURCES
+    ixwebsocket/IXCancellationRequest.cpp
+    ixwebsocket/IXConnectionState.cpp
+    ixwebsocket/IXDNSLookup.cpp
+    ixwebsocket/IXHttpClient.cpp
+    ixwebsocket/IXNetSystem.cpp
+    ixwebsocket/IXSelectInterrupt.cpp
+    ixwebsocket/IXSelectInterruptFactory.cpp
     ixwebsocket/IXSocket.cpp
-    ixwebsocket/IXSocketServer.cpp
     ixwebsocket/IXSocketConnect.cpp
     ixwebsocket/IXSocketFactory.cpp
-    ixwebsocket/IXDNSLookup.cpp
-    ixwebsocket/IXCancellationRequest.cpp
-    ixwebsocket/IXNetSystem.cpp
+    ixwebsocket/IXSocketServer.cpp
+    ixwebsocket/IXUrlParser.cpp
     ixwebsocket/IXWebSocket.cpp
-    ixwebsocket/IXWebSocketServer.cpp
-    ixwebsocket/IXWebSocketTransport.cpp
+    ixwebsocket/IXWebSocketCloseConstants.cpp
     ixwebsocket/IXWebSocketHandshake.cpp
+    ixwebsocket/IXWebSocketHttpHeaders.cpp
+    ixwebsocket/IXWebSocketMessageQueue.cpp
     ixwebsocket/IXWebSocketPerMessageDeflate.cpp
     ixwebsocket/IXWebSocketPerMessageDeflateCodec.cpp
     ixwebsocket/IXWebSocketPerMessageDeflateOptions.cpp
-    ixwebsocket/IXWebSocketHttpHeaders.cpp
-    ixwebsocket/IXHttpClient.cpp
-    ixwebsocket/IXUrlParser.cpp
+    ixwebsocket/IXWebSocketServer.cpp
+    ixwebsocket/IXWebSocketTransport.cpp
     ixwebsocket/LUrlParser.cpp
-    ixwebsocket/IXSelectInterrupt.cpp
-    ixwebsocket/IXSelectInterruptFactory.cpp
-    ixwebsocket/IXConnectionState.cpp
-    ixwebsocket/IXWebSocketCloseConstants.cpp
-    ixwebsocket/IXWebSocketMessageQueue.cpp
 )
 
 set( IXWEBSOCKET_HEADERS
-    ixwebsocket/IXSocket.h
-    ixwebsocket/IXSocketServer.h
-    ixwebsocket/IXSocketConnect.h
-    ixwebsocket/IXSocketFactory.h
-    ixwebsocket/IXSetThreadName.h
-    ixwebsocket/IXDNSLookup.h
     ixwebsocket/IXCancellationRequest.h
+    ixwebsocket/IXConnectionState.h
+    ixwebsocket/IXDNSLookup.h
+    ixwebsocket/IXHttpClient.h
     ixwebsocket/IXNetSystem.h
     ixwebsocket/IXProgressCallback.h
+    ixwebsocket/IXSelectInterrupt.h
+    ixwebsocket/IXSelectInterruptFactory.h
+    ixwebsocket/IXSetThreadName.h
+    ixwebsocket/IXSocket.h
+    ixwebsocket/IXSocketConnect.h
+    ixwebsocket/IXSocketFactory.h
+    ixwebsocket/IXSocketServer.h
+    ixwebsocket/IXUrlParser.h
     ixwebsocket/IXWebSocket.h
-    ixwebsocket/IXWebSocketServer.h
-    ixwebsocket/IXWebSocketTransport.h
-    ixwebsocket/IXWebSocketHandshake.h
-    ixwebsocket/IXWebSocketSendInfo.h
-    ixwebsocket/IXWebSocketErrorInfo.h
+    ixwebsocket/IXWebSocketCloseConstants.h
     ixwebsocket/IXWebSocketCloseInfo.h
-    ixwebsocket/IXWebSocketOpenInfo.h
-    ixwebsocket/IXWebSocketMessageType.h
+    ixwebsocket/IXWebSocketErrorInfo.h
+    ixwebsocket/IXWebSocketHandshake.h
+    ixwebsocket/IXWebSocketHttpHeaders.h
     ixwebsocket/IXWebSocketMessage.h
+    ixwebsocket/IXWebSocketMessageQueue.h
+    ixwebsocket/IXWebSocketMessageType.h
+    ixwebsocket/IXWebSocketOpenInfo.h
     ixwebsocket/IXWebSocketPerMessageDeflate.h
     ixwebsocket/IXWebSocketPerMessageDeflateCodec.h
     ixwebsocket/IXWebSocketPerMessageDeflateOptions.h
-    ixwebsocket/IXWebSocketHttpHeaders.h
-    ixwebsocket/libwshandshake.hpp
-    ixwebsocket/IXHttpClient.h
-    ixwebsocket/IXUrlParser.h
+    ixwebsocket/IXWebSocketSendInfo.h
+    ixwebsocket/IXWebSocketServer.h
+    ixwebsocket/IXWebSocketTransport.h
     ixwebsocket/LUrlParser.h
-    ixwebsocket/IXSelectInterrupt.h
-    ixwebsocket/IXSelectInterruptFactory.h
-    ixwebsocket/IXConnectionState.h
-    ixwebsocket/IXWebSocketCloseConstants.h
-    ixwebsocket/IXWebSocketMessageQueue.h
+    ixwebsocket/libwshandshake.hpp
 )
 
 if (UNIX)
@@ -141,25 +143,28 @@ if (USE_OPEN_SSL)
 endif()
 
 if (USE_MBED_TLS)
-  set (ENABLE_PROGRAMS OFF)
-  add_subdirectory(third_party/mbedtls)
-  include_directories(third_party/mbedtls/include)
+  if (USE_VENDORED_THIRD_PARTY)
+    set (ENABLE_PROGRAMS OFF)
+    add_subdirectory(third_party/mbedtls)
+    include_directories(third_party/mbedtls/include)
 
-  target_link_libraries(ixwebsocket mbedtls)
+    target_link_libraries(ixwebsocket mbedtls)
+  else()
+    find_package(MbedTLS REQUIRED)
+    include_directories(${MBEDTLS_INCLUDE_DIRS})
+    target_link_libraries(ixwebsocket ${MBEDTLS_LIBRARIES})
+  endif()
 endif()
 
-if (WIN32)
+find_package(ZLIB REQUIRED)
+if (ZLIB_FOUND)
+  include_directories(${ZLIB_INCLUDE_DIRS})
+  target_link_libraries(ixwebsocket ${ZLIB_LIBRARIES})
+else()
   add_subdirectory(third_party/zlib)
   include_directories(third_party/zlib ${CMAKE_CURRENT_BINARY_DIR}/third_party/zlib)
   target_link_libraries(ixwebsocket zlibstatic wsock32 ws2_32)
   add_definitions(-D_CRT_SECURE_NO_WARNINGS)
-
-else()
-  # gcc/Linux needs -pthread
-  find_package(Threads)
-
-  target_link_libraries(ixwebsocket 
-    z ${CMAKE_THREAD_LIBS_INIT})
 endif()
 
 set( IXWEBSOCKET_INCLUDE_DIRS
@@ -171,7 +176,7 @@ if (CMAKE_CXX_COMPILER_ID MATCHES "MSVC")
     target_compile_options(ixwebsocket PRIVATE /MP)
 endif()
 
-target_include_directories( ixwebsocket PUBLIC ${IXWEBSOCKET_INCLUDE_DIRS} )
+target_include_directories(ixwebsocket PUBLIC ${IXWEBSOCKET_INCLUDE_DIRS})
 
 set_target_properties(ixwebsocket PROPERTIES PUBLIC_HEADER "${IXWEBSOCKET_HEADERS}")