diff --git a/.github/workflows/.github.yml b/.github/workflows/.github.yml
index d3d87559..87f8bcb2 100644
--- a/.github/workflows/.github.yml
+++ b/.github/workflows/.github.yml
@@ -7,21 +7,39 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [ubuntu-latest]
-        compiler: [gcc, clang]
         include:
-          - compiler: gcc
-            cpp-compiler: g++
-          - compiler: clang
-            cpp-compiler: clang++
+          - os: ubuntu-latest
+            cc: gcc
+            cxx: g++
+          - os: ubuntu-latest
+            cc: clang
+            cxx: clang++
     env:
-      CC: ${{ matrix.compiler }}
-      CXX: ${{ matrix.cpp-compiler }}
+      CC: ${{ matrix.cc }}
+      CXX: ${{ matrix.cxx }}
     steps:
     - name: Checkout
       uses: actions/checkout@v2
+
+    - name: Get SDL2 headers
+      uses: actions/checkout@v2
+      with:
+        repository: libsdl-org/SDL
+        ref: release-2.0.9
+        path: SDL2
+    - name: Link SDL2 headers into system path
+      run: |
+        sudo ln -s "$GITHUB_WORKSPACE/SDL2/include" /usr/local/include/SDL2
+
     - name: Install dependencies
-      run: sudo apt-get -y install gcc-multilib g++-multilib libgl1-mesa-dev
-    - name: Build client and server on ${{ matrix.os }} with ${{ matrix.compiler }}
+      if: startsWith(matrix.os, 'ubuntu')
+      run: |
+        sudo apt-get -y install gcc-multilib g++-multilib
+
+    - name: Build with xash3d-fwgs input
       run: |
         cmake -B build -S . -DCMAKE_EXE_LINKER_FLAGS="-Wl,--no-undefined" && cmake --build build --target all
+    - name: Build with goldsource input
+      run: |
+        cmake -B build-gs -S . -DCMAKE_EXE_LINKER_FLAGS="-Wl,--no-undefined" -DGOLDSOURCE_SUPPORT=ON && cmake --build build-gs --target all
+
diff --git a/cl_dll/cdll_int.cpp b/cl_dll/cdll_int.cpp
index 4cbc2008..29edfbde 100644
--- a/cl_dll/cdll_int.cpp
+++ b/cl_dll/cdll_int.cpp
@@ -183,7 +183,7 @@ int *HUD_GetRect( void )
 	return extent;
 }
 
-#if USE_VGUI_FOR_GOLDSOURCE_SUPPORT
+#ifdef USE_VGUI_FOR_GOLDSOURCE_SUPPORT
 class TeamFortressViewport : public vgui::Panel
 {
 public:
@@ -238,7 +238,7 @@ so the HUD can reinitialize itself.
 int DLLEXPORT HUD_VidInit( void )
 {
 	gHUD.VidInit();
-#if USE_VGUI_FOR_GOLDSOURCE_SUPPORT
+#ifdef USE_VGUI_FOR_GOLDSOURCE_SUPPORT
 	vgui::Panel* root=(vgui::Panel*)gEngfuncs.VGui_GetPanel();
 	if (root) {
 		gEngfuncs.Con_Printf( "Root VGUI panel exists\n" );
@@ -337,7 +337,7 @@ Called by engine every frame that client .dll is loaded
 
 void DLLEXPORT HUD_Frame( double time )
 {
-#if USE_VGUI_FOR_GOLDSOURCE_SUPPORT
+#ifdef USE_VGUI_FOR_GOLDSOURCE_SUPPORT
 	if (!gViewPort)
 		gEngfuncs.VGui_ViewportPaintBackground(HUD_GetRect());
 #else
diff --git a/cl_dll/input_goldsource.cpp b/cl_dll/input_goldsource.cpp
index 1d1c9f8b..8698a5d3 100644
--- a/cl_dll/input_goldsource.cpp
+++ b/cl_dll/input_goldsource.cpp
@@ -10,7 +10,7 @@
 
 #include "input_mouse.h"
 
-#if SUPPORT_GOLDSOURCE_INPUT
+#ifdef SUPPORT_GOLDSOURCE_INPUT
 
 #include "hud.h"
 #include "cl_util.h"
@@ -27,7 +27,7 @@
 #define USE_SDL2
 #endif
 
-#if USE_SDL2
+#ifdef USE_SDL2
 #define ARRAYSIZE(p)		( sizeof(p) /sizeof(p[0]) )
 #include <dlfcn.h>
 #include <SDL2/SDL_mouse.h>
@@ -242,7 +242,7 @@ DWORD joy_oldbuttonstate, joy_oldpovstate;
 int joy_id;
 DWORD joy_numbuttons;
 
-#if USE_SDL2
+#ifdef USE_SDL2
 SDL_GameController *s_pJoystick = NULL;
 #elif defined(_WIN32)
 DWORD		joy_flags;
@@ -566,7 +566,7 @@ void GoldSourceInput::IN_Shutdown (void)
 	}
 #endif
 
-#if USE_SDL2
+#ifdef USE_SDL2
 	for (int j=0; j<ARRAYSIZE(sdlFunctions); ++j) {
 		*(sdlFunctions[j].ppfnFunc) = NULL;
 	}
@@ -735,7 +735,7 @@ void GoldSourceInput::IN_GetMouseDelta( int *pOutX, int *pOutY)
 		else
 #endif
 		{
-#if USE_SDL2
+#ifdef USE_SDL2
 			safe_pfnSDL_GetRelativeMouseState( &deltaX, &deltaY );
 			current_pos.x = deltaX;
 			current_pos.y = deltaY;
@@ -942,7 +942,7 @@ void GoldSourceInput::IN_Accumulate (void)
 			else
 #endif
 			{
-#if USE_SDL2
+#ifdef USE_SDL2
 				int deltaX, deltaY;
 				safe_pfnSDL_GetRelativeMouseState( &deltaX, &deltaY );
 				mx_accum += deltaX;
@@ -997,7 +997,7 @@ void IN_StartupJoystick (void)
 
 	// assume no joystick
 	joy_avail = 0;
-#if USE_SDL2
+#ifdef USE_SDL2
 	int nJoysticks = safe_pfnSDL_NumJoysticks();
 	if ( nJoysticks > 0 )
 	{
@@ -1084,7 +1084,7 @@ void IN_StartupJoystick (void)
 #endif
 }
 
-#if USE_SDL2
+#ifdef USE_SDL2
 int RawValuePointer (int axis)
 {
 	switch (axis)
@@ -1216,7 +1216,7 @@ void GoldSourceInput::IN_Commands (void)
 
 	// loop through the joystick buttons
 	// key a joystick event or auxillary event for higher number buttons for each state change
-#if USE_SDL2
+#ifdef USE_SDL2
 	buttonstate = 0;
 	for ( i = 0; i < SDL_CONTROLLER_BUTTON_MAX; i++ )
 	{
@@ -1294,7 +1294,7 @@ IN_ReadJoystick
 */
 int IN_ReadJoystick (void)
 {
-#if USE_SDL2
+#ifdef USE_SDL2
 	safe_pfnSDL_JoystickUpdate();
 	return 1;
 #elif defined(_WIN32)
@@ -1374,7 +1374,7 @@ void IN_JoyMove ( float frametime, usercmd_t *cmd )
 	for (i = 0; i < JOY_MAX_AXES; i++)
 	{
 		// get the floating point zero-centered, potentially-inverted data for the current axis
-#if USE_SDL2
+#ifdef USE_SDL2
 		fAxisValue = (float)pdwRawValue[i];
 #elif defined(_WIN32)
 		fAxisValue = (float) *pdwRawValue[i];
@@ -1600,7 +1600,7 @@ void GoldSourceInput::IN_Init (void)
 	}
 #endif
 
-#if USE_SDL2
+#ifdef USE_SDL2
 #if __APPLE__
 #define SDL2_FULL_LIBNAME "libsdl2-2.0.0.dylib"
 #else
diff --git a/cl_dll/input_mouse.cpp b/cl_dll/input_mouse.cpp
index c5b1df6b..3233d797 100644
--- a/cl_dll/input_mouse.cpp
+++ b/cl_dll/input_mouse.cpp
@@ -10,7 +10,7 @@ cvar_t  *in_joystick;
 
 FWGSInput fwgsInput;
 
-#if SUPPORT_GOLDSOURCE_INPUT
+#ifdef SUPPORT_GOLDSOURCE_INPUT
 GoldSourceInput goldSourceInput;
 AbstractInput* currentInput = &goldSourceInput;
 #else
@@ -68,7 +68,7 @@ void IN_Shutdown( void )
 
 void IN_Init( void )
 {
-#if SUPPORT_GOLDSOURCE_INPUT
+#ifdef SUPPORT_GOLDSOURCE_INPUT
 	if (IsXashFWGS()) {
 		gEngfuncs.Con_Printf( "FWGS Xash3D input is in use\n" );
 		currentInput = &fwgsInput;