diff --git a/CMakeLists.txt b/CMakeLists.txt
index f1ebba3240..b67e31838d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -689,7 +689,7 @@ dolphin_make_imported_target_if_missing(LibLZMA::LibLZMA LIBLZMA)
 
 dolphin_find_optional_system_library_pkgconfig(ZSTD libzstd>=1.4.0 zstd::zstd Externals/zstd)
 
-add_subdirectory(Externals/zlib-ng)
+dolphin_find_optional_system_library_pkgconfig(ZLIB zlib>=1.3.1 ZLIB::ZLIB Externals/zlib-ng)
 
 dolphin_find_optional_system_library_pkgconfig(MINIZIP
   "minizip>=4.0.4" minizip::minizip Externals/minizip-ng
diff --git a/Externals/minizip-ng/CMakeLists.txt b/Externals/minizip-ng/CMakeLists.txt
index 5929cef96d..39049eca1f 100644
--- a/Externals/minizip-ng/CMakeLists.txt
+++ b/Externals/minizip-ng/CMakeLists.txt
@@ -83,6 +83,7 @@ if (HAVE_INTTYPES_H)
   target_compile_definitions(minizip PRIVATE HAVE_INTTYPES_H)
 endif()
 
+include(CheckFunctionExists)
 check_function_exists(fseeko HAVE_FSEEKO)
 if (NOT HAVE_FSEEKO)
   target_compile_definitions(minizip PRIVATE NO_FSEEKO)