diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5b56f9a4ea..628f877e98 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -166,7 +166,7 @@ if(ENABLE_GENERIC)
 	message(STATUS "Warning! Building generic build!")
 	set(_M_GENERIC 1)
 	add_definitions(-D_M_GENERIC=1)
-elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "x86_64|amd64|AMD64")
+elseif(_ARCH_64 AND CMAKE_SYSTEM_PROCESSOR MATCHES "x86_64|amd64|AMD64")
 	set(_M_X86 1)
 	set(_M_X86_64 1)
 	add_definitions(-D_M_X86=1)
@@ -180,7 +180,9 @@ elseif(CMAKE_SYSTEM_PROCESSOR STREQUAL "aarch64")
 	# CRC instruction set is used in the CRC32 hash function
 	check_and_add_flag(HAVE_ARCH_ARMV8 -march=armv8-a+crc)
 else()
-	message(FATAL_ERROR "You're building on an unsupported platform '${CMAKE_SYSTEM_PROCESSOR}'. Enable generic build if you really want a JIT-less binary.")
+	message(FATAL_ERROR "You're building on an unsupported platform: "
+		"'${CMAKE_SYSTEM_PROCESSOR}' with ${CMAKE_SIZEOF_VOID_P}-byte pointers."
+		" Enable generic build if you really want a JIT-less binary.")
 endif()
 
 
@@ -242,16 +244,7 @@ else()
 	endif()
 endif()
 
-if(CMAKE_SYSTEM_NAME MATCHES "Windows")
-	add_definitions(-DNOMINMAX)
-	add_definitions(-DUNICODE)
-	add_definitions(-D_UNICODE)
-	add_definitions(-DWIN32_LEAN_AND_MEAN)
-	add_definitions(-D_WIN32_WINNT=0x0602)
-	add_definitions(-D_SECURE_SCL=0)
-	add_definitions(-D_CRT_SECURE_NO_WARNINGS)
-	add_definitions(-D_CRT_SECURE_NO_DEPRECATE)
-elseif(CMAKE_SYSTEM_NAME MATCHES "Darwin")
+if(CMAKE_SYSTEM_NAME MATCHES "Darwin")
 	# This doesn't play well with the packaging script that doesn't understand @rpath
 	set(CMAKE_MACOSX_RPATH OFF)
 
@@ -575,6 +568,9 @@ if(NOT ANDROID)
 		set(PORTAUDIO_LIBRARIES portaudio)
 	else()
 		message(STATUS "Using static PortAudio from Externals for mic support")
+		option(PA_USE_ASIO "Enable PortAudio support for ASIO" OFF)
+		option(PA_USE_DS "Enable PortAudio support for DirectSound" OFF)
+		option(PA_USE_WDMKS "Enable PortAudio support for WDMKS" OFF)
 		add_subdirectory(Externals/portaudio)
 		set(PORTAUDIO_LIBRARIES portaudio_static)
 	endif()
diff --git a/Source/CMakeLists.txt b/Source/CMakeLists.txt
index 9d886827f4..e1836da317 100644
--- a/Source/CMakeLists.txt
+++ b/Source/CMakeLists.txt
@@ -3,6 +3,17 @@ if(NOT FLAG_CXX_CXX14)
   check_and_add_flag(HAS_CXX1Y -std=c++1y)
 endif()
 
+if(CMAKE_SYSTEM_NAME MATCHES "Windows")
+  add_definitions(-DNOMINMAX)
+  add_definitions(-DUNICODE)
+  add_definitions(-D_UNICODE)
+  add_definitions(-DWIN32_LEAN_AND_MEAN)
+  add_definitions(-D_WIN32_WINNT=0x0602)
+  add_definitions(-D_SECURE_SCL=0)
+  add_definitions(-D_CRT_SECURE_NO_WARNINGS)
+  add_definitions(-D_CRT_SECURE_NO_DEPRECATE)
+endif()
+
 # These aren't actually needed for C11/C++11
 # but some dependencies require them (LLVM, libav).
 add_definitions(-D__STDC_LIMIT_MACROS)