diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index ba354c289..e303850a9 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -227,6 +227,10 @@ set(SRB2_CONFIG_YASM OFF CACHE BOOL
 set(SRB2_CONFIG_STATIC_OPENGL OFF CACHE BOOL
 	"Use statically linked OpenGL. NOT RECOMMENDED.")
 
+### use internal libraries?
+set(SRB2_CONFIG_USE_INTERNAL_LIBRARIES OFF CACHE BOOL
+	"Use SRB2's internal copies of required dependencies (SDL2, PNG, zlib, GME).")
+
 if(${SRB2_CONFIG_HAVE_BLUA})
 	add_definitions(-DHAVE_BLUA)
 	set(SRB2_LUA_SOURCES
@@ -314,7 +318,13 @@ if(${SRB2_CONFIG_HAVE_BLUA})
 endif()
 
 if(${SRB2_CONFIG_HAVE_GME})
-	find_package(GME)
+	if(${SRB2_CONFIG_USE_INTERNAL_LIBRARIES})
+		set(GME_FOUND ON)
+		set(GME_INCLUDE_DIRS ${CMAKE_SOURCE_DIR}/libs/gme/include)
+		set(GME_LIBRARIES "-L${CMAKE_SOURCE_DIR}/libs/gme/ -lgme")
+	else()
+		find_package(GME)
+	endif()
 	if(${GME_FOUND})
 		set(SRB2_HAVE_GME ON)
 		add_definitions(-DHAVE_LIBGME)
@@ -324,7 +334,13 @@ if(${SRB2_CONFIG_HAVE_GME})
 endif()
 
 if(${SRB2_CONFIG_HAVE_ZLIB})
-	find_package(ZLIB)
+	if(${SRB2_CONFIG_USE_INTERNAL_LIBRARIES})
+		set(ZLIB_FOUND ON)
+		set(ZLIB_INCLUDE_DIRS ${CMAKE_SOURCE_DIR}/libs/zlib)
+		set(ZLIB_LIBRARIES "-L${CMAKE_SOURCE_DIR}/libs/zlib/win32 -lz32")
+	else()
+		find_package(ZLIB)
+	endif()
 	if(${ZLIB_FOUND})
 		set(SRB2_HAVE_ZLIB ON)
 	else()
@@ -334,7 +350,13 @@ endif()
 
 if(${SRB2_CONFIG_HAVE_PNG} AND ${SRB2_CONFIG_HAVE_ZLIB})
 	if (${ZLIB_FOUND})
-		find_package(PNG)
+		if(${SRB2_CONFIG_USE_INTERNAL_LIBRARIES})
+			set(PNG_FOUND ON)
+			set(PNG_INCLUDE_DIRS ${CMAKE_SOURCE_DIR}/libs/libpng-src)
+			set(PNG_LIBRARIES "-L${CMAKE_SOURCE_DIR}/libs/libpng-src/projects -lpng32")
+		else()
+			find_package(PNG)
+		endif()
 		if(${PNG_FOUND})
 			set(SRB2_HAVE_PNG ON)
 			add_definitions(-DHAVE_PNG)
diff --git a/src/sdl/CMakeLists.txt b/src/sdl/CMakeLists.txt
index 7f6771262..e929558cd 100644
--- a/src/sdl/CMakeLists.txt
+++ b/src/sdl/CMakeLists.txt
@@ -3,7 +3,13 @@
 set(SRB2_CONFIG_SDL2_USEMIXER ON CACHE BOOL "Use SDL2_mixer or regular sdl sound")
 
 if(${SRB2_CONFIG_SDL2_USEMIXER})
-	find_package(SDL2_mixer)
+	if(${SRB2_CONFIG_USE_INTERNAL_LIBRARIES})
+		set(SDL2_MIXER_FOUND ON)
+		set(SDL2_MIXER_INCLUDE_DIRS ${CMAKE_SOURCE_DIR}/libs/SDL2_mixer/i686-w64-mingw32/include/SDL2)
+		set(SDL2_MIXER_LIBRARIES "-L${CMAKE_SOURCE_DIR}/libs/SDL2_mixer/i686-w64-mingw32/lib -lSDL2_mixer")
+	else()
+		find_package(SDL2_mixer)
+	endif()
 	if(${SDL2_MIXER_FOUND})
 		set(SRB2_HAVE_MIXER ON)
 		set(SRB2_SDL2_SOUNDIMPL mixer_sound.c)
@@ -42,7 +48,13 @@ set(SRB2_SDL2_HEADERS
 source_group("Interface Code" FILES ${SRB2_SDL2_SOURCES} ${SRB2_SDL2_HEADERS})
 
 # Dependency
-find_package(SDL2)
+if(${SRB2_CONFIG_USE_INTERNAL_LIBRARIES})
+	set(SDL2_FOUND ON)
+	set(SDL2_INCLUDE_DIRS ${CMAKE_SOURCE_DIR}/libs/SDL2/i686-w64-mingw32/include/SDL2)
+	set(SDL2_LIBRARIES "-L${CMAKE_SOURCE_DIR}/libs/SDL2/i686-w64-mingw32/lib -lSDL2")
+else()
+	find_package(SDL2)
+endif()
 
 if(${SDL2_FOUND})
 	set(SRB2_SDL2_TOTAL_SOURCES
@@ -185,7 +197,13 @@ if(${SDL2_FOUND})
 	endif()
 
 	if(MSVC)
-		find_package(SDL2_MAIN REQUIRED)
+		if(${SRB2_CONFIG_USE_INTERNAL_LIBRARIES})
+			set(SDL2_MAIN_FOUND ON)
+			set(SDL2_MAIN_INCLUDE_DIRS ${CMAKE_SOURCE_DIR}/libs/SDL2/i686-w64-mingw32/include/SDL2)
+			set(SDL2_MAIN_LIBRARIES "-L${CMAKE_SOURCE_DIR}/libs/SDL2/i686-w64-mingw32/lib -lSDL2main")
+		else()
+			find_package(SDL2_MAIN REQUIRED)
+		endif()
 		target_link_libraries(SRB2SDL2 PRIVATE
 			${SDL2_MAIN_LIBRARIES}
 		)