diff --git a/.gitignore b/.gitignore
index 7023aaa80..3eca1c57a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -21,3 +21,4 @@ Win32_LIB_ASM_Release
 /assets/debian
 /make
 /bin
+/build
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6e52d740d..915912af5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,5 +1,9 @@
 cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
 
+if("${CMAKE_CURRENT_BINARY_DIR}" STREQUAL "${CMAKE_CURRENT_SOURCE_DIR}")
+	message(FATAL_ERROR "In-source builds are blocked. Please build from a separate directory.")
+endif()
+
 # Set up CMAKE path
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake/Modules/")
 
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 973fd01d1..c6459de3c 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -1,6 +1,6 @@
 add_executable(SRB2SDL2 MACOSX_BUNDLE WIN32)
 
-if("${CMAKE_COMPILER_IS_GNUCC}" AND "${CMAKE_SYSTEM_NAME}" MATCHES "Windows" AND NOT "${SRB2_CONFIG_SYSTEM_LIBRARIES}")
+if("${CMAKE_COMPILER_IS_GNUCC}" AND "${CMAKE_SYSTEM_NAME}" MATCHES "Windows" AND NOT "${SRB2_CONFIG_SYSTEM_LIBRARIES}" AND NOT "${SRB2_CONFIG_SHARED_INTERNAL_LIBRARIES}")
 	# On MinGW with internal libraries, link the standard library statically
 	target_link_options(SRB2SDL2 PRIVATE "-static")
 endif()
@@ -303,3 +303,27 @@ if((CMAKE_COMPILER_IS_GNUCC) AND NOT ("${CMAKE_SYSTEM_NAME}" MATCHES Darwin))
 		)
 	endif()
 endif()
+
+# copy DLLs to bin/ directory if building internal shared on windows
+if("${CMAKE_SYSTEM_NAME}" STREQUAL Windows AND NOT "${SRB2_CONFIG_INTERNAL_LIBRARIES}" AND "${SRB2_CONFIG_SHARED_INTERNAL_LIBRARIES}")
+	set(ADDITIONAL_DLLS "")
+	if("${CMAKE_C_COMPILER_ID}" STREQUAL GNU)
+		# also copy implicitly linked system libraries
+		get_filename_component(MINGW_BIN_PATH ${CMAKE_CXX_COMPILER} PATH)
+		list(APPEND ADDITIONAL_DLLS
+			"libgcc_s_dw2-1.dll"
+			"libstdc++-6.dll"
+			"libwinpthread-1.dll"
+		)
+		list(TRANSFORM ADDITIONAL_DLLS PREPEND "${MINGW_BIN_PATH}/")
+	endif()
+	add_custom_command(TARGET SRB2SDL2 POST_BUILD
+		COMMAND ${CMAKE_COMMAND} -E copy_if_different
+			$<TARGET_RUNTIME_DLLS:SRB2SDL2>
+			${ADDITIONAL_DLLS}
+
+			$<TARGET_FILE_DIR:SRB2SDL2>
+		COMMAND_EXPAND_LISTS
+		COMMENT "Copying runtime DLLs"
+	)
+endif()
diff --git a/thirdparty/CMakeLists.txt b/thirdparty/CMakeLists.txt
index 208044113..37c36399a 100644
--- a/thirdparty/CMakeLists.txt
+++ b/thirdparty/CMakeLists.txt
@@ -57,30 +57,52 @@ if(NOT "${SRB2_CONFIG_SYSTEM_LIBRARIES}")
 		VERSION 1.2.13
 		URL "https://github.com/madler/zlib/archive/refs/tags/v1.2.13.zip"
 		EXCLUDE_FROM_ALL
-		OPTIONS
-			# The assembly optimizations are unmaintained and slated to be removed
-			"ASM686 Off"
-			"AMD64 Off"
-			"SKIP_INSTALL_ALL ON"
+		DOWNLOAD_ONLY YES
 	)
-	file(MAKE_DIRECTORY "${zlib_BINARY_DIR}/include")
-	file(COPY "${zlib_SOURCE_DIR}/zlib.h" DESTINATION "${zlib_BINARY_DIR}/include")
-	file(COPY "${zlib_BINARY_DIR}/zconf.h" DESTINATION "${zlib_BINARY_DIR}/include")
-	# honestly this should probably be built like png is
-	set_target_properties(zlib PROPERTIES EXCLUDE_FROM_ALL ON)
-	set_target_properties(minigzip PROPERTIES EXCLUDE_FROM_ALL ON)
-	set_target_properties(example PROPERTIES EXCLUDE_FROM_ALL ON)
-	# zlib cmake also adds these 64 targets separately
-	if(HAVE_OFF64_T)
-		set_target_properties(minigzip64 PROPERTIES EXCLUDE_FROM_ALL ON)
-		set_target_properties(example64 PROPERTIES EXCLUDE_FROM_ALL ON)
-	endif()
-	target_include_directories(zlib INTERFACE "${zlib_BINARY_DIR}/include")
-	target_include_directories(zlibstatic INTERFACE "${zlib_BINARY_DIR}/include")
-	if(SRB2_CONFIG_SHARED_INTERNAL_LIBRARIES)
-		add_library(ZLIB::ZLIB ALIAS zlib)
-	else()
-		add_library(ZLIB::ZLIB ALIAS zlibstatic)
+	if(ZLIB_ADDED)
+		set(ZLIB_SRCS
+			crc32.h
+			deflate.h
+			gzguts.h
+			inffast.h
+			inffixed.h
+			inflate.h
+			inftrees.h
+			trees.h
+			zutil.h
+
+			adler32.c
+			compress.c
+			crc32.c
+			deflate.c
+			gzclose.c
+			gzlib.c
+			gzread.c
+			gzwrite.c
+			inflate.c
+			infback.c
+			inftrees.c
+			inffast.c
+			trees.c
+			uncompr.c
+			zutil.c
+		)
+		list(TRANSFORM ZLIB_SRCS PREPEND "${ZLIB_SOURCE_DIR}/")
+		
+		configure_file("${ZLIB_SOURCE_DIR}/zlib.pc.cmakein" "${ZLIB_BINARY_DIR}/zlib.pc" @ONLY)
+		configure_file("${ZLIB_SOURCE_DIR}/zconf.h.cmakein" "${ZLIB_BINARY_DIR}/include/zconf.h" @ONLY)
+
+		add_library(ZLIB ${SRB2_INTERNAL_LIBRARY_TYPE} ${ZLIB_SRCS})
+		set_target_properties(ZLIB PROPERTIES
+			VERSION 1.2.13
+			OUTPUT_NAME "z"
+		)
+		target_include_directories(ZLIB PRIVATE "${ZLIB_SOURCE_DIR}")
+		target_include_directories(ZLIB PUBLIC "${ZLIB_BINARY_DIR}/include")
+		if(MSVC)
+			target_compile_definitions(ZLIB PRIVATE -D_CRT_SECURE_NO_DEPRECATE -D_CRT_NONSTDC_NO_DEPRECATE)
+		endif()
+		add_library(ZLIB::ZLIB ALIAS ZLIB)
 	endif()
 endif()
 
@@ -470,6 +492,12 @@ if(NOT "${SRB2_CONFIG_SYSTEM_LIBRARIES}")
 		# -DLIBOPENMPT_BUILD
 		configure_file("openmpt_svn_version.h" "svn_version.h")
 		add_library(openmpt "${SRB2_INTERNAL_LIBRARY_TYPE}" ${openmpt_SOURCES} ${CMAKE_CURRENT_BINARY_DIR}/svn_version.h)
+		if("${CMAKE_C_COMPILER_ID}" STREQUAL GNU OR "${CMAKE_C_COMPILER_ID}" STREQUAL Clang OR "${CMAKE_C_COMPILER_ID}" STREQUAL AppleClang)
+			target_compile_options(openmpt PRIVATE "-g0")
+		endif()
+		if("${CMAKE_SYSTEM_NAME}" STREQUAL Windows)
+			target_link_libraries(openmpt PRIVATE Rpcrt4)
+		endif()
 		target_compile_features(openmpt PRIVATE cxx_std_11)
 		target_compile_definitions(openmpt PRIVATE -DLIBOPENMPT_BUILD)