diff --git a/CMakeLists.txt b/CMakeLists.txt
index dfda7cb7c..a9dbda4cc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -656,19 +656,42 @@ if(CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang")
 	)
 
 	# Due to a regression in gcc-4.8.X, we need to disable array-bounds check
-	IF (CMAKE_COMPILER_IS_GNUCXX AND ((CMAKE_CXX_COMPILER_VERSION VERSION_EQUAL "4.8.0") OR (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER "4.8.0") OR LMMS_BUILD_WIN32))
-		SET(WERROR_FLAGS "${WERROR_FLAGS} -Wno-array-bounds -Wno-attributes")
-	ENDIF()
-ELSEIF(MSVC)
-	# Remove any existing /W flags
-	string(REGEX REPLACE "/W[0-4]" "" CMAKE_C_FLAGS ${CMAKE_C_FLAGS})
-	STRING(REGEX REPLACE "/W[0-4]" "" CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS})
-	SET(WERROR_FLAGS "/W2")
-	IF(${USE_WERROR})
-		SET(WERROR_FLAGS "${WERROR_FLAGS} /WX")
-	ENDIF()
-ENDIF()
+	# TODO: Is this still necessary?
+	if(CMAKE_COMPILER_IS_GNUCXX)
+		list(APPEND COMPILE_ERROR_FLAGS
+			"-Wno-array-bounds" # Permit out-of-bounds array subscripts
+			"-Wno-attributes" # Permit unrecognised attributes
+		)
+	endif()
 
+	if(USE_WERROR)
+		list(APPEND COMPILE_ERROR_FLAGS
+			"-Werror" # Treat warnings as errors
+		)
+	endif()
+elseif(MSVC)
+	set(COMPILE_ERROR_FLAGS
+		"/W2" # Enable some warnings by default
+		"/external:W0" # Don't emit warnings for third-party code
+		"/external:anglebrackets" # Consider headers included with angle brackets to be third-party
+		"/external:templates-" # Still emit warnings from first-party instantiations of third-party templates
+		# Silence "class X needs to have DLL-interface to be used by clients of
+		# class Y" warnings. These aren't trivial to address, and don't pose a
+		# problem for us since we build all modules with the same compiler and
+		# options, and dynamically link the CRT.
+		"/wd4251"
+	)
+	set(THIRD_PARTY_COMPILE_ERROR_FLAGS
+		"/W0" # Disable all warnings
+	)
+
+	if(USE_WERROR)
+		list(APPEND COMPILE_ERROR_FLAGS
+			"/WX" # Treat warnings as errors
+		)
+	endif()
+endif()
+add_compile_options("$<IF:$<BOOL:$<TARGET_PROPERTY:SYSTEM>>,${THIRD_PARTY_COMPILE_ERROR_FLAGS},${COMPILE_ERROR_FLAGS}>")
 
 IF(NOT CMAKE_BUILD_TYPE)
 	message(STATUS "Setting build type to 'Release' as none was specified.")
diff --git a/plugins/ZynAddSubFx/CMakeLists.txt b/plugins/ZynAddSubFx/CMakeLists.txt
index d9f723961..b3490a50f 100644
--- a/plugins/ZynAddSubFx/CMakeLists.txt
+++ b/plugins/ZynAddSubFx/CMakeLists.txt
@@ -111,15 +111,6 @@ set_target_properties(zynaddsubfx_nio PROPERTIES SYSTEM TRUE)
 set_target_properties(zynaddsubfx_gui PROPERTIES SYSTEM TRUE)
 set_target_properties(zynaddsubfx_synth PROPERTIES SYSTEM TRUE)
 
-<<<<<<< HEAD
-if(MINGW)
-	target_link_libraries(zynaddsubfx_nio PUBLIC mingw_stdthreads)
-	target_link_libraries(zynaddsubfx_gui PUBLIC mingw_stdthreads)
-	target_link_libraries(zynaddsubfx_synth PUBLIC mingw_stdthreads)
-endif()
-
-=======
->>>>>>> master
 # Relative include paths don't work automatically for the GUI, because the
 # generated C++ files aren't in the source directory. Thus, add the expected
 # source directory as an additional include directory.
diff --git a/src/3rdparty/CMakeLists.txt b/src/3rdparty/CMakeLists.txt
index e648cfd03..e5cb62527 100644
--- a/src/3rdparty/CMakeLists.txt
+++ b/src/3rdparty/CMakeLists.txt
@@ -11,15 +11,6 @@ target_include_directories(jack_headers INTERFACE jack2/common)
 ADD_SUBDIRECTORY(hiir)
 ADD_SUBDIRECTORY(weakjack)
 
-<<<<<<< HEAD
-if(MINGW)
-	option(MINGW_STDTHREADS_GENERATE_STDHEADERS "" ON)
-	add_subdirectory(mingw-std-threads)
-	set(LMMS_USE_MINGW_STD_THREADS ON PARENT_SCOPE)
-endif()
-
-=======
->>>>>>> master
 # The lockless ring buffer library is linked as part of the core
 add_library(ringbuffer OBJECT
 	ringbuffer/src/lib/ringbuffer.cpp