diff --git a/CMakeLists.txt b/CMakeLists.txt
index 961902e..cc522cf 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -16,7 +16,6 @@ include(GNUInstallDirs)
 find_package(Threads REQUIRED)
 
 option(VERBOSE "Build efsw with verbose mode.")
-option(LEGACY "Build efsw with cpp legacy support (before C++11).")
 option(BUILD_SHARED_LIBS "Build efsw as a shared library" ON)
 option(BUILD_STATIC_LIBS "Build efsw as a static library" ON)
 option(BUILD_TEST_APP "Build the test app" ${ESFW_MAIN_PROJECT})
@@ -68,11 +67,7 @@ if(VERBOSE)
 	target_compile_definitions(efsw PRIVATE EFSW_VERBOSE)
 endif()
 
-if(NOT LEGACY)
-	target_compile_features(efsw PRIVATE cxx_std_11)
-else()
-	target_compile_definitions(efsw PRIVATE EFSW_LEGACY_CPP)
-endif()
+target_compile_features(efsw PRIVATE cxx_std_11)
 
 if(BUILD_SHARED_LIBS)
 	target_compile_definitions(efsw PRIVATE EFSW_DYNAMIC EFSW_EXPORTS)
diff --git a/premake4.lua b/premake4.lua
index 785eefc..2918390 100644
--- a/premake4.lua
+++ b/premake4.lua
@@ -1,6 +1,5 @@
 newoption { trigger = "verbose", description = "Build efsw with verbose mode." }
 newoption { trigger = "strip-symbols", description = "Strip debugging symbols in other file ( only for relwithdbginfo configuration )." }
-newoption { trigger = "legacy", description = "Build efsw with cpp legacy support (before C++11)." }
 newoption { trigger = "thread-sanitizer", description ="Compile with ThreadSanitizer." }
 
 efsw_major_version	= "1"
@@ -133,12 +132,8 @@ solution "efsw"
 		defines { "EFSW_VERBOSE" }
 	end
 
-	if not _OPTIONS["legacy"] then
-		if not is_vs() then
-			buildoptions { "-std=c++11" }
-		end
-	else
-		defines { "EFSW_LEGACY_CPP" }
+	if not is_vs() then
+		buildoptions { "-std=c++11" }
 	end
 
 	if os.is("macosx") then
diff --git a/premake5.lua b/premake5.lua
index d97c80b..9f993b1 100644
--- a/premake5.lua
+++ b/premake5.lua
@@ -1,6 +1,5 @@
 newoption { trigger = "verbose", description = "Build efsw with verbose mode." }
 newoption { trigger = "strip-symbols", description = "Strip debugging symbols in other file ( only for relwithdbginfo configuration )." }
-newoption { trigger = "legacy", description = "Build efsw with cpp legacy support (before C++11)." }
 newoption { trigger = "thread-sanitizer", description ="Compile with ThreadSanitizer" }
 
 efsw_major_version	= "1"
@@ -134,11 +133,7 @@ workspace "efsw"
 		defines { "EFSW_VERBOSE" }
 	end
 
-	if not _OPTIONS["legacy"] then
-		cppdialect "C++11"
-	else
-		defines { "EFSW_LEGACY_CPP" }
-	end
+	cppdialect "C++11"
 
 	objdir("obj/" .. os.target() .. "/")
 
diff --git a/src/efsw/Atomic.hpp b/src/efsw/Atomic.hpp
index 420207a..9015c60 100644
--- a/src/efsw/Atomic.hpp
+++ b/src/efsw/Atomic.hpp
@@ -3,9 +3,7 @@
 
 #include <efsw/base.hpp>
 
-#ifndef EFSW_LEGACY_CPP
 #include <atomic>
-#endif
 
 namespace efsw {
 
@@ -14,36 +12,20 @@ template <typename T> class Atomic {
 	explicit Atomic( T set = false ) : set_( set ) {}
 
 	Atomic& operator=( T set ) {
-#ifndef EFSW_LEGACY_CPP
 		set_.store( set, std::memory_order_release );
-#else
-		set_ = set;
-#endif
 		return *this;
 	}
 
 	explicit operator T() const {
-#ifndef EFSW_LEGACY_CPP
 		return set_.load( std::memory_order_acquire );
-#else
-		return set_;
-#endif
 	}
 
 	T load() const {
-#ifndef EFSW_LEGACY_CPP
 		return set_.load( std::memory_order_acquire );
-#else
-		return set_;
-#endif
 	}
 
   private:
-#ifndef EFSW_LEGACY_CPP
 	std::atomic<T> set_;
-#else
-	volatile T set_;
-#endif
 };
 
 } // namespace efsw
diff --git a/src/efsw/FileWatcherFSEvents.cpp b/src/efsw/FileWatcherFSEvents.cpp
index 03c6f21..0fa7452 100644
--- a/src/efsw/FileWatcherFSEvents.cpp
+++ b/src/efsw/FileWatcherFSEvents.cpp
@@ -72,9 +72,7 @@ FileWatcherFSEvents::FileWatcherFSEvents( FileWatcher* parent ) :
 FileWatcherFSEvents::~FileWatcherFSEvents() {
 	mInitOK = false;
 
-#ifndef EFSW_LEGACY_CPP
 	mWatchCond.notify_all();
-#endif
 
 	WatchMap::iterator iter = mWatches.begin();
 
@@ -135,9 +133,7 @@ WatchID FileWatcherFSEvents::addWatch( const std::string& directory, FileWatchLi
 		mWatches.insert( std::make_pair( mLastWatchID, pWatch ) );
 	}
 
-#ifndef EFSW_LEGACY_CPP
 	mWatchCond.notify_all();
-#endif
 	return pWatch->ID;
 }
 
diff --git a/src/efsw/FileWatcherFSEvents.hpp b/src/efsw/FileWatcherFSEvents.hpp
index ca59fa0..6eb87e8 100644
--- a/src/efsw/FileWatcherFSEvents.hpp
+++ b/src/efsw/FileWatcherFSEvents.hpp
@@ -11,10 +11,8 @@
 #include <efsw/WatcherFSEvents.hpp>
 #include <map>
 #include <vector>
-#ifndef EFSW_LEGACY_CPP
 #include <condition_variable>
 #include <mutex>
-#endif
 
 namespace efsw {
 
@@ -91,10 +89,8 @@ class FileWatcherFSEvents : public FileWatcherImpl {
 
 	bool pathInWatches( const std::string& path );
 
-#ifndef EFSW_LEGACY_CPP
 	std::mutex mWatchesMutex;
 	std::condition_variable mWatchCond;
-#endif
 
 };