diff --git a/Makefile b/Makefile
index 7f09eaad..604fd122 100644
--- a/Makefile
+++ b/Makefile
@@ -207,10 +207,18 @@ ifndef USE_INTERNAL_LIBS
 USE_INTERNAL_LIBS=1
 endif
 
+ifndef USE_INTERNAL_CURL_HEADERS
+USE_INTERNAL_CURL_HEADERS=$(USE_INTERNAL_LIBS)
+endif
+
 ifndef USE_INTERNAL_OGG
 USE_INTERNAL_OGG=$(USE_INTERNAL_LIBS)
 endif
 
+ifndef USE_INTERNAL_OPENAL_HEADERS
+USE_INTERNAL_OPENAL_HEADERS=$(USE_INTERNAL_LIBS)
+endif
+
 ifndef USE_INTERNAL_VORBIS
 USE_INTERNAL_VORBIS=$(USE_INTERNAL_LIBS)
 endif
@@ -219,6 +227,10 @@ ifndef USE_INTERNAL_OPUS
 USE_INTERNAL_OPUS=$(USE_INTERNAL_LIBS)
 endif
 
+ifndef USE_INTERNAL_SDL
+USE_INTERNAL_SDL=$(USE_INTERNAL_LIBS)
+endif
+
 ifndef USE_INTERNAL_ZLIB
 USE_INTERNAL_ZLIB=$(USE_INTERNAL_LIBS)
 endif
@@ -540,7 +552,7 @@ ifeq ($(PLATFORM),darwin)
   CLIENT_LIBS += -framework IOKit
   RENDERER_LIBS += -framework OpenGL
 
-  ifeq ($(USE_LOCAL_HEADERS),1)
+  ifeq ($(USE_INTERNAL_SDL),1)
     BASE_CFLAGS += -I$(SDLHDIR)/include
 
     # We copy sdlmain before ranlib'ing it so that subversion doesn't think
@@ -697,7 +709,7 @@ ifdef MINGW
   CLIENT_LIBS += -lmingw32
   RENDERER_LIBS += -lmingw32
 
-  ifeq ($(USE_LOCAL_HEADERS),1)
+  ifeq ($(USE_INTERNAL_SDL),1)
     CLIENT_CFLAGS += -I$(SDLHDIR)/include
     ifeq ($(ARCH),x86)
     CLIENT_LIBS += $(LIBSDIR)/win32/libSDL2main.a \
@@ -1277,8 +1289,20 @@ ifdef DEFAULT_BASEDIR
   BASE_CFLAGS += -DDEFAULT_BASEDIR=\\\"$(DEFAULT_BASEDIR)\\\"
 endif
 
-ifeq ($(USE_LOCAL_HEADERS),1)
-  BASE_CFLAGS += -DUSE_LOCAL_HEADERS
+ifeq ($(USE_INTERNAL_OPENAL_HEADERS),1)
+  BASE_CFLAGS += -DUSE_INTERNAL_OPENAL_HEADERS
+endif
+
+ifeq ($(USE_INTERNAL_CURL_HEADERS),1)
+  BASE_CFLAGS += -DUSE_INTERNAL_CURL_HEADERS
+endif
+
+ifeq ($(USE_INTERNAL_SDL),1)
+  BASE_CFLAGS += -DUSE_INTERNAL_SDL_HEADERS
+endif
+
+ifeq ($(USE_INTERNAL_ZLIB),1)
+  BASE_CFLAGS += -DUSE_INTERNAL_ZLIB
 endif
 
 ifeq ($(BUILD_STANDALONE),1)
diff --git a/code/client/cl_http_curl.c b/code/client/cl_http_curl.c
index f88bff26..3cfbc5b2 100644
--- a/code/client/cl_http_curl.c
+++ b/code/client/cl_http_curl.c
@@ -24,7 +24,7 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 
 #include "client.h"
 
-#ifdef USE_LOCAL_HEADERS
+#ifdef USE_INTERNAL_CURL_HEADERS
   #include "curl/curl.h"
 #else
   #include <curl/curl.h>
diff --git a/code/client/qal.h b/code/client/qal.h
index 2585db4e..977c434e 100644
--- a/code/client/qal.h
+++ b/code/client/qal.h
@@ -33,7 +33,7 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 #define ALC_NO_PROTOTYPES
 #endif
 
-#ifdef USE_LOCAL_HEADERS
+#ifdef USE_INTERNAL_OPENAL_HEADERS
 #include "AL/al.h"
 #include "AL/alc.h"
 #else
diff --git a/code/qcommon/ioapi.c b/code/qcommon/ioapi.c
index 96962e88..ff394b3c 100644
--- a/code/qcommon/ioapi.c
+++ b/code/qcommon/ioapi.c
@@ -10,7 +10,7 @@
 #include <stdlib.h>
 #include <string.h>
 
-#ifdef USE_LOCAL_HEADERS
+#ifdef USE_INTERNAL_ZLIB
 #include "zlib.h"
 #else
 #include <zlib.h>
diff --git a/code/qcommon/unzip.h b/code/qcommon/unzip.h
index 86ef0919..8e1a73ec 100644
--- a/code/qcommon/unzip.h
+++ b/code/qcommon/unzip.h
@@ -49,7 +49,7 @@
 extern "C" {
 #endif
 
-#ifdef USE_LOCAL_HEADERS
+#ifdef USE_INTERNAL_ZLIB
   #include "zlib.h"
 #else
   #include <zlib.h>
diff --git a/code/renderercommon/qgl.h b/code/renderercommon/qgl.h
index f226e408..512cdefc 100644
--- a/code/renderercommon/qgl.h
+++ b/code/renderercommon/qgl.h
@@ -26,7 +26,7 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 #ifndef __QGL_H__
 #define __QGL_H__
 
-#ifdef USE_LOCAL_HEADERS
+#ifdef USE_INTERNAL_SDL_HEADERS
 #	include "SDL_opengl.h"
 #else
 #	include <SDL_opengl.h>
diff --git a/code/renderergl2/tr_extensions.c b/code/renderergl2/tr_extensions.c
index 856526bf..b8efe6a5 100644
--- a/code/renderergl2/tr_extensions.c
+++ b/code/renderergl2/tr_extensions.c
@@ -21,7 +21,7 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
 // tr_extensions.c - extensions needed by the renderer not in sdl_glimp.c
 
-#ifdef USE_LOCAL_HEADERS
+#ifdef USE_INTERNAL_SDL_HEADERS
 #	include "SDL.h"
 #else
 #	include <SDL.h>
diff --git a/code/sdl/sdl_gamma.c b/code/sdl/sdl_gamma.c
index a1e0cb5b..f4b5c812 100644
--- a/code/sdl/sdl_gamma.c
+++ b/code/sdl/sdl_gamma.c
@@ -20,7 +20,7 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 ===========================================================================
 */
 
-#ifdef USE_LOCAL_HEADERS
+#ifdef USE_INTERNAL_SDL_HEADERS
 #	include "SDL.h"
 #else
 #	include <SDL.h>
diff --git a/code/sdl/sdl_glimp.c b/code/sdl/sdl_glimp.c
index 5ce1e47d..74e1ec50 100644
--- a/code/sdl/sdl_glimp.c
+++ b/code/sdl/sdl_glimp.c
@@ -20,7 +20,7 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 ===========================================================================
 */
 
-#ifdef USE_LOCAL_HEADERS
+#ifdef USE_INTERNAL_SDL_HEADERS
 #	include "SDL.h"
 #else
 #	include <SDL.h>
diff --git a/code/sdl/sdl_input.c b/code/sdl/sdl_input.c
index 1660cf75..145f39bb 100644
--- a/code/sdl/sdl_input.c
+++ b/code/sdl/sdl_input.c
@@ -20,7 +20,7 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 ===========================================================================
 */
 
-#ifdef USE_LOCAL_HEADERS
+#ifdef USE_INTERNAL_SDL_HEADERS
 #	include "SDL.h"
 #else
 #	include <SDL.h>
diff --git a/code/sdl/sdl_snd.c b/code/sdl/sdl_snd.c
index 7696a515..e8d04a38 100644
--- a/code/sdl/sdl_snd.c
+++ b/code/sdl/sdl_snd.c
@@ -23,7 +23,7 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 #include <stdlib.h>
 #include <stdio.h>
 
-#ifdef USE_LOCAL_HEADERS
+#ifdef USE_INTERNAL_SDL_HEADERS
 #	include "SDL.h"
 #else
 #	include <SDL.h>
diff --git a/code/sys/sys_loadlib.h b/code/sys/sys_loadlib.h
index 0b1eac3e..eac0f2c7 100644
--- a/code/sys/sys_loadlib.h
+++ b/code/sys/sys_loadlib.h
@@ -35,7 +35,7 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 #		define Sys_LibraryError() dlerror()
 #	endif
 #else
-#	ifdef USE_LOCAL_HEADERS
+#	ifdef USE_INTERNAL_SDL_HEADERS
 #		include "SDL.h"
 #		include "SDL_loadso.h"
 #	else
diff --git a/code/sys/sys_local.h b/code/sys/sys_local.h
index 248a51cd..a0d6dc24 100644
--- a/code/sys/sys_local.h
+++ b/code/sys/sys_local.h
@@ -24,7 +24,7 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 #include "../qcommon/qcommon.h"
 
 #ifndef DEDICATED
-#ifdef USE_LOCAL_HEADERS
+#ifdef USE_INTERNAL_SDL_HEADERS
 #	include "SDL_version.h"
 #else
 #	include <SDL_version.h>
diff --git a/code/sys/sys_main.c b/code/sys/sys_main.c
index d7341806..83b2c986 100644
--- a/code/sys/sys_main.c
+++ b/code/sys/sys_main.c
@@ -36,7 +36,7 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 #endif
 
 #ifndef DEDICATED
-#ifdef USE_LOCAL_HEADERS
+#ifdef USE_INTERNAL_SDL_HEADERS
 #	include "SDL.h"
 #	include "SDL_cpuinfo.h"
 #else