diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index de630b4e..1e8755ab 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -4,7 +4,7 @@ on: [push, pull_request]
 jobs:
   linux:
     name: Linux
-    runs-on: ubuntu-16.04
+    runs-on: ubuntu-18.04
     steps:
     - uses: actions/checkout@v2
     - name: Install Dependencies
diff --git a/code/qcommon/files.c b/code/qcommon/files.c
index 4a94463e..a9f2995a 100644
--- a/code/qcommon/files.c
+++ b/code/qcommon/files.c
@@ -2932,7 +2932,9 @@ void FS_AddGameDirectory( const char *path, const char *dir ) {
 	// Get .pk3 files
 	pakfiles = Sys_ListFiles(curpath, ".pk3", NULL, &numfiles, qfalse);
 
-	qsort( pakfiles, numfiles, sizeof(char*), paksort );
+	if ( pakfiles ) {
+		qsort( pakfiles, numfiles, sizeof(char*), paksort );
+	}
 
 	if ( fs_numServerPaks ) {
 		numdirs = 0;
diff --git a/code/renderergl2/glsl/lightall_fp.glsl b/code/renderergl2/glsl/lightall_fp.glsl
index ff7fc125..28b59eb7 100644
--- a/code/renderergl2/glsl/lightall_fp.glsl
+++ b/code/renderergl2/glsl/lightall_fp.glsl
@@ -264,7 +264,8 @@ void main()
 	float NL, NH, NE, EH, attenuation;
 
 #if defined(USE_LIGHT) && !defined(USE_FAST_LIGHT)
-	mat3 tangentToWorld = mat3(var_Tangent.xyz, var_Bitangent.xyz, var_Normal.xyz);
+	vec3 surfNormal = (!gl_FrontFacing ? var_Normal : -var_Normal).xyz;
+	mat3 tangentToWorld = mat3(var_Tangent.xyz, var_Bitangent.xyz, surfNormal);
 	viewDir = vec3(var_Normal.w, var_Tangent.w, var_Bitangent.w);
 	E = normalize(viewDir);
 #endif
@@ -335,7 +336,7 @@ void main()
 	N.z = sqrt(clamp((0.25 - N.x * N.x) - N.y * N.y, 0.0, 1.0));
 	N = tangentToWorld * N;
   #else
-	N = var_Normal.xyz;
+	N = surfNormal;
   #endif
 
 	N = normalize(N);
@@ -361,7 +362,7 @@ void main()
 
   #if !defined(USE_LIGHT_VECTOR)
 	ambientColor = lightColor;
-	float surfNL = clamp(dot(var_Normal.xyz, L), 0.0, 1.0);
+	float surfNL = clamp(dot(surfNormal, L), 0.0, 1.0);
 
 	// reserve 25% ambient to avoid black areas on normalmaps
 	lightColor *= 0.75;
diff --git a/code/sdl/sdl_input.c b/code/sdl/sdl_input.c
index 2ad324e3..63274c61 100644
--- a/code/sdl/sdl_input.c
+++ b/code/sdl/sdl_input.c
@@ -33,6 +33,10 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 #include "../client/client.h"
 #include "../sys/sys_local.h"
 
+#if !SDL_VERSION_ATLEAST(2, 0, 17)
+#define KMOD_SCROLL KMOD_RESERVED
+#endif
+
 static cvar_t *in_keyboardDebug     = NULL;
 
 static SDL_GameController *gamepad = NULL;
@@ -84,7 +88,7 @@ static void IN_PrintKey( const SDL_Keysym *keysym, keyNum_t key, qboolean down )
 	if( keysym->mod & KMOD_NUM )      Com_Printf( " KMOD_NUM" );
 	if( keysym->mod & KMOD_CAPS )     Com_Printf( " KMOD_CAPS" );
 	if( keysym->mod & KMOD_MODE )     Com_Printf( " KMOD_MODE" );
-	if( keysym->mod & KMOD_RESERVED ) Com_Printf( " KMOD_RESERVED" );
+	if( keysym->mod & KMOD_SCROLL )   Com_Printf( " KMOD_SCROLL" );
 
 	Com_Printf( " Q:0x%02x(%s)\n", key, Key_KeynumToString( key ) );
 }