diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 0c29e52e6..39c8aadd9 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -91,3 +91,21 @@ jobs:
     - name: Build dedicated linux-amd64
       run: |
         scripts/build-ubuntu-amd64.sh -d
+
+  build-macos-amd64:
+    runs-on: macos-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Build macos-amd64
+      run: |
+        scripts/build-macos-amd64.sh
+
+  build-dedicated-macos-amd64:
+    runs-on: macos-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Build dedicated macos-amd64
+      run: |
+        scripts/build-macos-amd64.sh -d
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index c21d0a55a..d8adc5ab0 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -21,6 +21,15 @@ jobs:
       run: |
         scripts/tests-ubuntu-amd64.sh
 
+  tests-macos-amd64:
+    runs-on: macos-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Run tests macos-amd64
+      run: |
+        scripts/tests-macos-amd64.sh
+
   tests-windows-i386:
     runs-on: windows-2019
 
diff --git a/appframework/sdlmgr.cpp b/appframework/sdlmgr.cpp
index bad06f1b5..dd5ee2c23 100644
--- a/appframework/sdlmgr.cpp
+++ b/appframework/sdlmgr.cpp
@@ -2224,7 +2224,7 @@ GLMDisplayDB *CSDLMgr::GetDisplayDB( void )
 }
 
 #ifndef OSX
-# include "glmdisplaydb_linuxwin.inl"
+#include "glmdisplaydb_linuxwin.inl"
 #endif
 
 
diff --git a/appframework/wscript b/appframework/wscript
index 0fea261a1..f8ded3183 100755
--- a/appframework/wscript
+++ b/appframework/wscript
@@ -24,11 +24,10 @@ def build(bld):
 		source += [
 			'sdlmgr.cpp'
 		]
-	
-	if bld.env.DEST_OS == 'darwin':
-		source += [
-			'glmrendererinfo_osx.mm'
-		]
+
+	if bld.env.DEST_OS == 'darwin' and bld.env.GL:
+		source += ['glmrendererinfo_osx.mm']
+
 
 	if bld.env.DEST_OS == 'win32':
 		source += [
diff --git a/filesystem/filesystem_async.cpp b/filesystem/filesystem_async.cpp
index 769ed017c..493b1b705 100644
--- a/filesystem/filesystem_async.cpp
+++ b/filesystem/filesystem_async.cpp
@@ -659,8 +659,9 @@ void CBaseFileSystem::InitAsync()
 		Msg( "Async I/O disabled from command line\n" );
 		return;
 	}
-
+#ifndef UNITTESTS
 	if ( VCRGetMode() == VCR_Disabled )
+#endif
 	{
 		// create the i/o thread pool
 		m_pThreadPool = CreateThreadPool();
@@ -668,7 +669,6 @@ void CBaseFileSystem::InitAsync()
 		ThreadPoolStartParams_t params;
 		params.iThreadPriority = 0;
 		params.bIOThreads = true;
-		params.nThreadsMax = 4; // Limit count of IO threads to a maximum of 4.
 		if ( IsX360() )
 		{
 			// override defaults
@@ -678,11 +678,10 @@ void CBaseFileSystem::InitAsync()
 			params.bUseAffinityTable = true;
 			params.iAffinityTable[0] = XBOX_PROCESSOR_3;
 		}
-		else if( IsPC() )
+		else
 		{
-			// override defaults
-			// maximum # of async I/O thread on PC is 2
-			params.nThreads = 1;
+			params.nThreadsMax = MIN(params.nThreads, 4); // Limit count of IO threads to a maximum of 4.
+			params.nStackSize = 256*1024;
 		}
 
 		if ( !m_pThreadPool->Start( params, "IOJob" ) )
diff --git a/scripts/build-macos-amd64.sh b/scripts/build-macos-amd64.sh
new file mode 100755
index 000000000..de0e8cfd1
--- /dev/null
+++ b/scripts/build-macos-amd64.sh
@@ -0,0 +1,8 @@
+#!/bin/sh
+
+git submodule init && git submodule update
+
+brew install sdl2
+
+./waf configure -T debug --64bits --disable-warns $* &&
+./waf build
diff --git a/scripts/tests-macos-amd64.sh b/scripts/tests-macos-amd64.sh
new file mode 100755
index 000000000..ff4e46b27
--- /dev/null
+++ b/scripts/tests-macos-amd64.sh
@@ -0,0 +1,7 @@
+#!/bin/sh
+
+git submodule init && git submodule update
+./waf configure -T release --sanitize=address,undefined --disable-warns --tests -8 --prefix=out/ $* &&
+./waf install &&
+cd out &&
+DYLD_LIBRARY_PATH=bin/ ./unittest || exit 1
diff --git a/wscript b/wscript
index 7441473c2..d41481e9f 100644
--- a/wscript
+++ b/wscript
@@ -159,15 +159,17 @@ def define_platform(conf):
 	conf.env.DEDICATED = conf.options.DEDICATED
 	conf.env.TESTS = conf.options.TESTS
 	conf.env.TOGLES = conf.options.TOGLES
-	conf.env.GL = conf.options.GL
+	conf.env.GL = conf.options.GL and not conf.options.TESTS and not conf.options.DEDICATED
 	conf.env.OPUS = conf.options.OPUS
 
 	if conf.options.DEDICATED:
 		conf.options.SDL = False
-#		conf.options.GL = False
 		conf.define('DEDICATED', 1)
 
-	if conf.options.GL and not conf.options.TESTS:
+	if conf.options.TESTS:
+		conf.define('UNITTESTS', 1)
+
+	if conf.options.GL:
 		conf.env.append_unique('DEFINES', [
 			'DX_TO_GL_ABSTRACTION',
 			'GL_GLEXT_PROTOTYPES',
@@ -177,6 +179,9 @@ def define_platform(conf):
 	if conf.options.TOGLES:
 		conf.env.append_unique('DEFINES', ['TOGLES'])
 
+	if conf.options.TESTS:
+		conf.define('UNITTESTS', 1)
+
 	if conf.options.SDL and not conf.options.TESTS:
 		conf.env.SDL = 1
 		conf.define('USE_SDL', 1)
@@ -323,6 +328,20 @@ def check_deps(conf):
 			for i in a:
 				conf.check_cc(lib = i)
 
+	if conf.env.DEST_OS == "darwin":
+		conf.check(lib='iconv', uselib_store='ICONV')
+		conf.env.FRAMEWORK_APPKIT = "AppKit"
+		conf.env.FRAMEWORK_IOKIT = "IOKit"
+		conf.env.FRAMEWORK_FOUNDATION = "Foundation"
+		conf.env.FRAMEWORK_COREFOUNDATION = "CoreFoundation"
+		conf.env.FRAMEWORK_COREGRAPHICS = "CoreGraphics"
+		conf.env.FRAMEWORK_OPENGL = "OpenGL"
+		conf.env.FRAMEWORK_CARBON = "Carbon"
+		conf.env.FRAMEWORK_APPLICATIONSERVICES = "ApplicationServices"
+		conf.env.FRAMEWORK_CORESERVICES = "CoreServices"
+		conf.env.FRAMEWORK_COREAUDIO = "CoreAudio"
+		conf.env.FRAMEWORK_AUDIOTOOLBOX = "AudioToolbox"
+		conf.env.FRAMEWORK_SYSTEMCONFIGURATION = "SystemConfiguration"
 
 	if conf.options.TESTS:
 		return
@@ -361,21 +380,6 @@ def check_deps(conf):
 		conf.check(lib='android_support', uselib_store='ANDROID_SUPPORT')
 		conf.check(lib='opus', uselib_store='OPUS')
 
-	if conf.env.DEST_OS == "darwin":
-		conf.check(lib='iconv', uselib_store='ICONV')
-		conf.env.FRAMEWORK_APPKIT = "AppKit"
-		conf.env.FRAMEWORK_IOKIT = "IOKit"
-		conf.env.FRAMEWORK_FOUNDATION = "Foundation"
-		conf.env.FRAMEWORK_COREFOUNDATION = "CoreFoundation"
-		conf.env.FRAMEWORK_COREGRAPHICS = "CoreGraphics"
-		conf.env.FRAMEWORK_OPENGL = "OpenGL"
-		conf.env.FRAMEWORK_CARBON = "Carbon"
-		conf.env.FRAMEWORK_APPLICATIONSERVICES = "ApplicationServices"
-		conf.env.FRAMEWORK_CORESERVICES = "CoreServices"
-		conf.env.FRAMEWORK_COREAUDIO = "CoreAudio"
-		conf.env.FRAMEWORK_AUDIOTOOLBOX = "AudioToolbox"
-		conf.env.FRAMEWORK_SYSTEMCONFIGURATION = "SystemConfiguration"
-
 	if conf.env.DEST_OS == 'win32':
 		conf.check(lib='libz', uselib_store='ZLIB', define_name='USE_ZLIB')
 		# conf.check(lib='nvtc', uselib_store='NVTC')