diff --git a/SConstruct b/SConstruct
index 129bc98aa82..5f1f63c0d1c 100644
--- a/SConstruct
+++ b/SConstruct
@@ -134,7 +134,6 @@ opts.Add('speex','Speex library for speex support','builtin')
 opts.Add('xml','XML Save/Load support (yes/no)','yes')
 opts.Add('libpng','libpng library for image loader support (system/builtin)','builtin')
 opts.Add('libwebp','libwebp library for webp module (system/builtin)','builtin')
-opts.Add('builtin_zlib','Use built-in zlib (yes/no)','yes')
 opts.Add('openssl','OpenSSL library for openssl module (system/builtin)','builtin')
 opts.Add('libmpcdec','libmpcdec library for mpc module (system/builtin)','builtin')
 opts.Add('glew','GLEW library for the gl_context (system/builtin)','builtin')
@@ -323,9 +322,6 @@ if selected_platform in platform_list:
 	if (env.use_ptrcall):
 		env.Append(CPPFLAGS=['-DPTRCALL_ENABLED']);
 
-	if (env["builtin_zlib"]=='yes'):
-		env.Append(CPPPATH=['#drivers/builtin_zlib/zlib'])
-
 	# to test 64 bits compiltion
 	# env.Append(CPPFLAGS=['-m64'])
 
diff --git a/drivers/SCsub b/drivers/SCsub
index bc0d948f41b..edab83cd869 100644
--- a/drivers/SCsub
+++ b/drivers/SCsub
@@ -15,8 +15,8 @@ SConscript('gles2/SCsub');
 SConscript('gl_context/SCsub');
 
 SConscript("png/SCsub");
-if (env["builtin_zlib"]=="yes"):
-	SConscript("builtin_zlib/SCsub");
+if ("builtin_zlib" in env and env["builtin_zlib"] == "yes"):
+	SConscript("zlib/SCsub");
 
 if (env["platform"] == "windows"):
 	SConscript("rtaudio/SCsub");
diff --git a/drivers/builtin_zlib/SCsub b/drivers/builtin_zlib/SCsub
deleted file mode 100644
index e5c81c0b3b1..00000000000
--- a/drivers/builtin_zlib/SCsub
+++ /dev/null
@@ -1,22 +0,0 @@
-Import('env')
-
-zlib_sources = [
-
-	"builtin_zlib/zlib/adler32.c",
-	"builtin_zlib/zlib/compress.c",
-	"builtin_zlib/zlib/crc32.c",
-	"builtin_zlib/zlib/deflate.c",
-	"builtin_zlib/zlib/infback.c",
-	"builtin_zlib/zlib/inffast.c",
-	"builtin_zlib/zlib/inflate.c",
-	"builtin_zlib/zlib/inftrees.c",
-	"builtin_zlib/zlib/trees.c",
-	"builtin_zlib/zlib/uncompr.c",
-	"builtin_zlib/zlib/zutil.c",
-	]
-
-
-env.drivers_sources+=zlib_sources
-
-#env.add_source_files("core", png_sources)
-Export('env')
diff --git a/drivers/zlib/SCsub b/drivers/zlib/SCsub
new file mode 100644
index 00000000000..d0bbcd452ba
--- /dev/null
+++ b/drivers/zlib/SCsub
@@ -0,0 +1,24 @@
+Import('env')
+
+# Not cloning the env, the includes need to be accessible for core/
+
+# Thirdparty source files
+# No check here as already done in drivers/SCsub
+thirdparty_dir = "#thirdparty/zlib/"
+thirdparty_sources = [
+	"adler32.c",
+	"compress.c",
+	"crc32.c",
+	"deflate.c",
+	"infback.c",
+	"inffast.c",
+	"inflate.c",
+	"inftrees.c",
+	"trees.c",
+	"uncompr.c",
+	"zutil.c",
+]
+thirdparty_sources = [thirdparty_dir + file for file in thirdparty_sources]
+
+env.add_source_files(env.drivers_sources, thirdparty_sources)
+env.Append(CPPPATH = [thirdparty_dir])
diff --git a/platform/android/detect.py b/platform/android/detect.py
index a94aae3c29d..99a3b740c7e 100644
--- a/platform/android/detect.py
+++ b/platform/android/detect.py
@@ -34,7 +34,6 @@ def get_flags():
 
 	return [
 		('tools', 'no'),
-		('builtin_zlib', 'no'),
 		('openssl', 'builtin'), #use builtin openssl
 	]
 
diff --git a/platform/bb10/detect.py b/platform/bb10/detect.py
index 5aa68b36dcb..2b76aa34967 100644
--- a/platform/bb10/detect.py
+++ b/platform/bb10/detect.py
@@ -33,6 +33,7 @@ def get_flags():
 
 	return [
 		('tools', 'no'),
+		('builtin_zlib', 'yes'),
 		('module_theora_enabled', 'no'),
 	]
 
diff --git a/platform/haiku/detect.py b/platform/haiku/detect.py
index 8aa810e18d8..af997a57372 100644
--- a/platform/haiku/detect.py
+++ b/platform/haiku/detect.py
@@ -23,7 +23,6 @@ def get_opts():
 
 def get_flags():
 	return [
-		('builtin_zlib', 'no'),
 	]
 
 def configure(env):
diff --git a/platform/iphone/detect.py b/platform/iphone/detect.py
index 3de0ba0db9d..1be63891b16 100644
--- a/platform/iphone/detect.py
+++ b/platform/iphone/detect.py
@@ -38,6 +38,7 @@ def get_flags():
 	return [
 		('tools', 'no'),
 		('webp', 'yes'),
+		('builtin_zlib', 'yes'),
 		('openssl','builtin'), #use builtin openssl
 	]
 
diff --git a/platform/javascript/detect.py b/platform/javascript/detect.py
index b0f02d27e9c..821a1dab696 100644
--- a/platform/javascript/detect.py
+++ b/platform/javascript/detect.py
@@ -25,6 +25,7 @@ def get_flags():
 
 	return [
 		('tools', 'no'),
+		('builtin_zlib', 'yes'),
 		('module_speex_enabled', 'no'),
 		('module_etc1_enabled', 'no'),
 		('module_mpc_enabled', 'no'),
diff --git a/platform/osx/detect.py b/platform/osx/detect.py
index 43ddfa0d1a6..2ade0978930 100644
--- a/platform/osx/detect.py
+++ b/platform/osx/detect.py
@@ -28,7 +28,6 @@ def get_opts():
 def get_flags():
 
 	return [
-		('builtin_zlib', 'no'),
 	]
 
 
diff --git a/platform/server/detect.py b/platform/server/detect.py
index 543c88c5c24..2f6fb00e0d2 100644
--- a/platform/server/detect.py
+++ b/platform/server/detect.py
@@ -27,7 +27,6 @@ def get_opts():
 def get_flags():
 
 	return [
-		('builtin_zlib', 'no'),
 	]
 
 
diff --git a/platform/windows/detect.py b/platform/windows/detect.py
index 925c33a5111..6ee866640bc 100644
--- a/platform/windows/detect.py
+++ b/platform/windows/detect.py
@@ -168,6 +168,7 @@ def get_opts():
 def get_flags():
 
 	return [
+		('builtin_zlib', 'yes'),
 		('openssl','builtin'), #use builtin openssl
 	]
 
diff --git a/platform/x11/detect.py b/platform/x11/detect.py
index c4055030f6a..53bcf667abe 100644
--- a/platform/x11/detect.py
+++ b/platform/x11/detect.py
@@ -68,7 +68,6 @@ def get_opts():
 def get_flags():
 
 	return [
-	('builtin_zlib', 'no'),
 	("openssl", "system"),
 	('freetype','yes'), # use system freetype
 	('libpng', 'system'),
diff --git a/thirdparty/README.md b/thirdparty/README.md
index de55254eebc..91f6d4ddff2 100644
--- a/thirdparty/README.md
+++ b/thirdparty/README.md
@@ -9,7 +9,7 @@
 
 Files extracted from upstream source:
 
-- src/glew.c
+- `src/glew.c`
 - include/GL/ as GL/
 - LICENSE.txt
 
@@ -22,7 +22,7 @@ Files extracted from upstream source:
 
 Files extracted from upstream source:
 
-- jpgd.{c,h}
+- `jpgd.{c,h}`
 
 
 ## libmpcdec
@@ -46,8 +46,8 @@ Files extracted from upstream source:
 
 Files extracted from upstream source:
 
-- src/\*.c
-- include/ogg/\*.h in ogg/
+- `src/*.c`
+- `include/ogg/*.h` in ogg/
 - COPYING
 
 
@@ -59,11 +59,10 @@ Files extracted from upstream source:
 
 Files extracted from upstream source:
 
-- all .c and .h files of the main directory, except from:
-  * example.c
-  * pngtest.c
+- all .c and .h files of the main directory, except from
+  `example.c` and `pngtest.c`
 - the arm/ folder
-- scripts/pnglibconf.h.prebuilt as pnglibconf.h
+- `scripts/pnglibconf.h.prebuilt` as `pnglibconf.h`
 
 
 ## libvorbis
@@ -74,8 +73,8 @@ Files extracted from upstream source:
 
 Files extracted from upstream source:
 
-- src/\* except from: lookups.pl, Makefile.\*
-- include/vorbis/\*.h as vorbis/
+- `src/*` except from: `lookups.pl`, `Makefile.*`
+- `include/vorbis/*.h` as vorbis/
 - COPYING
 
 
@@ -87,7 +86,7 @@ Files extracted from upstream source:
 
 Files extracted from the upstream source:
 
-- src/\* except from: \*.am, \*.in, extras/, webp/extras.h
+- `src/*` except from: .am and .in, files, extras/, `webp/extras.h`
 - AUTHORS, COPYING, PATENTS
 
 Important: The files `utils/bit_reader.{c,h}` have Godot-made
@@ -115,7 +114,7 @@ TODO.
 Files extracted from upstream source:
 
 - all .c and .h files in src/ (both opus and opusfile),
-  except opus_demo.c
+  except `opus_demo.c`
 - all .h files in include/ (both opus and opusfile)
 - COPYING
 
@@ -128,7 +127,7 @@ Files extracted from upstream source:
 
 Files extracted from upstream source:
 
-- all .cpp and .h files apart from main.cpp
+- all .cpp and .h files apart from `main.cpp`
 - LICENSE.TXT
 
 
@@ -140,7 +139,7 @@ Files extracted from upstream source:
 
 Files extracted from upstream source:
 
-- all of them: rg_etc1.{cpp,h}
+- `rg_etc1.{cpp,h}`
 
 
 ## rtaudio
@@ -151,7 +150,7 @@ Files extracted from upstream source:
 
 Files extracted from upstream source:
 
-- RtAudio.{cpp,h}
+- `RtAudio.{cpp,h}`
 
 
 ## speex
@@ -184,3 +183,14 @@ Files extracted from upstream source:
 - all .c, .h in lib/
 - all .h files in include/theora/ as theora/
 - COPYING and LICENSE
+
+
+## zlib
+
+- Upstream: http://www.zlib.net/
+- Version: 1.2.8
+- License: zlib
+
+Files extracted from upstream source:
+
+- all .c and .h files apart from `gz*`
diff --git a/drivers/builtin_zlib/zlib/adler32.c b/thirdparty/zlib/adler32.c
similarity index 100%
rename from drivers/builtin_zlib/zlib/adler32.c
rename to thirdparty/zlib/adler32.c
diff --git a/drivers/builtin_zlib/zlib/compress.c b/thirdparty/zlib/compress.c
similarity index 100%
rename from drivers/builtin_zlib/zlib/compress.c
rename to thirdparty/zlib/compress.c
diff --git a/drivers/builtin_zlib/zlib/crc32.c b/thirdparty/zlib/crc32.c
similarity index 100%
rename from drivers/builtin_zlib/zlib/crc32.c
rename to thirdparty/zlib/crc32.c
diff --git a/drivers/builtin_zlib/zlib/crc32.h b/thirdparty/zlib/crc32.h
similarity index 100%
rename from drivers/builtin_zlib/zlib/crc32.h
rename to thirdparty/zlib/crc32.h
diff --git a/drivers/builtin_zlib/zlib/deflate.c b/thirdparty/zlib/deflate.c
similarity index 100%
rename from drivers/builtin_zlib/zlib/deflate.c
rename to thirdparty/zlib/deflate.c
diff --git a/drivers/builtin_zlib/zlib/deflate.h b/thirdparty/zlib/deflate.h
similarity index 100%
rename from drivers/builtin_zlib/zlib/deflate.h
rename to thirdparty/zlib/deflate.h
diff --git a/drivers/builtin_zlib/zlib/infback.c b/thirdparty/zlib/infback.c
similarity index 100%
rename from drivers/builtin_zlib/zlib/infback.c
rename to thirdparty/zlib/infback.c
diff --git a/drivers/builtin_zlib/zlib/inffast.c b/thirdparty/zlib/inffast.c
similarity index 100%
rename from drivers/builtin_zlib/zlib/inffast.c
rename to thirdparty/zlib/inffast.c
diff --git a/drivers/builtin_zlib/zlib/inffast.h b/thirdparty/zlib/inffast.h
similarity index 100%
rename from drivers/builtin_zlib/zlib/inffast.h
rename to thirdparty/zlib/inffast.h
diff --git a/drivers/builtin_zlib/zlib/inffixed.h b/thirdparty/zlib/inffixed.h
similarity index 100%
rename from drivers/builtin_zlib/zlib/inffixed.h
rename to thirdparty/zlib/inffixed.h
diff --git a/drivers/builtin_zlib/zlib/inflate.c b/thirdparty/zlib/inflate.c
similarity index 100%
rename from drivers/builtin_zlib/zlib/inflate.c
rename to thirdparty/zlib/inflate.c
diff --git a/drivers/builtin_zlib/zlib/inflate.h b/thirdparty/zlib/inflate.h
similarity index 100%
rename from drivers/builtin_zlib/zlib/inflate.h
rename to thirdparty/zlib/inflate.h
diff --git a/drivers/builtin_zlib/zlib/inftrees.c b/thirdparty/zlib/inftrees.c
similarity index 100%
rename from drivers/builtin_zlib/zlib/inftrees.c
rename to thirdparty/zlib/inftrees.c
diff --git a/drivers/builtin_zlib/zlib/inftrees.h b/thirdparty/zlib/inftrees.h
similarity index 100%
rename from drivers/builtin_zlib/zlib/inftrees.h
rename to thirdparty/zlib/inftrees.h
diff --git a/drivers/builtin_zlib/zlib/trees.c b/thirdparty/zlib/trees.c
similarity index 100%
rename from drivers/builtin_zlib/zlib/trees.c
rename to thirdparty/zlib/trees.c
diff --git a/drivers/builtin_zlib/zlib/trees.h b/thirdparty/zlib/trees.h
similarity index 100%
rename from drivers/builtin_zlib/zlib/trees.h
rename to thirdparty/zlib/trees.h
diff --git a/drivers/builtin_zlib/zlib/uncompr.c b/thirdparty/zlib/uncompr.c
similarity index 100%
rename from drivers/builtin_zlib/zlib/uncompr.c
rename to thirdparty/zlib/uncompr.c
diff --git a/drivers/builtin_zlib/zlib/zconf.h b/thirdparty/zlib/zconf.h
similarity index 100%
rename from drivers/builtin_zlib/zlib/zconf.h
rename to thirdparty/zlib/zconf.h
diff --git a/drivers/builtin_zlib/zlib/zlib.h b/thirdparty/zlib/zlib.h
similarity index 100%
rename from drivers/builtin_zlib/zlib/zlib.h
rename to thirdparty/zlib/zlib.h
diff --git a/drivers/builtin_zlib/zlib/zutil.c b/thirdparty/zlib/zutil.c
similarity index 100%
rename from drivers/builtin_zlib/zlib/zutil.c
rename to thirdparty/zlib/zutil.c
diff --git a/drivers/builtin_zlib/zlib/zutil.h b/thirdparty/zlib/zutil.h
similarity index 100%
rename from drivers/builtin_zlib/zlib/zutil.h
rename to thirdparty/zlib/zutil.h