diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5f9dbbd..23b24ed 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -3,7 +3,11 @@ cmake_minimum_required (VERSION 3.0)
 project (Simple-Web-Server)
 
 option(USE_STANDALONE_ASIO "set ON to use standalone Asio instead of Boost.Asio" OFF)
-option(BUILD_TESTING "set ON to build library tests" OFF)
+if(CMAKE_SOURCE_DIR STREQUAL "${CMAKE_CURRENT_SOURCE_DIR}")
+    option(BUILD_TESTING "set ON to build library tests" ON)
+else()
+    option(BUILD_TESTING "set ON to build library tests" OFF)
+endif()
 option(BUILD_FUZZING "set ON to build library fuzzers" OFF)
 option(USE_OPENSSL "set OFF to build without OpenSSL" ON)
 
@@ -75,7 +79,6 @@ if(CMAKE_SOURCE_DIR STREQUAL "${CMAKE_CURRENT_SOURCE_DIR}")
             target_include_directories(https_examples PRIVATE ${Boost_INCLUDE_DIR})
         endif()
      endif()
-    set(BUILD_TESTING ON)
 
     install(FILES asio_compatibility.hpp server_http.hpp client_http.hpp server_https.hpp client_https.hpp crypto.hpp utility.hpp status_code.hpp mutex.hpp DESTINATION include/simple-web-server)
 endif()