diff --git a/Libraries/LibCore/CMakeLists.txt b/Libraries/LibCore/CMakeLists.txt
index 7465c41290d..d3136184d5b 100644
--- a/Libraries/LibCore/CMakeLists.txt
+++ b/Libraries/LibCore/CMakeLists.txt
@@ -22,6 +22,10 @@ serenity_lib(LibCoreMinimal coreminimal)
 if (WIN32)
     find_path(DIRENT_INCLUDE_DIR dirent.h REQUIRED)
     target_include_directories(LibCoreMinimal PRIVATE ${DIRENT_INCLUDE_DIR})
+
+    find_package(mman REQUIRED)
+    target_include_directories(LibCoreMinimal PRIVATE ${MMAN_INCLUDE_DIR})
+    target_link_libraries(LibCoreMinimal PRIVATE ${MMAN_LIBRARY})
 endif()
 
 if (LAGOM_TOOLS_ONLY)
@@ -110,3 +114,7 @@ endif()
 if (ANDROID)
     target_link_libraries(LibCore PRIVATE log)
 endif()
+
+if (WIN32)
+    target_include_directories(LibCore PRIVATE ${MMAN_INCLUDE_DIR})
+endif()
diff --git a/Libraries/LibCore/MappedFile.cpp b/Libraries/LibCore/MappedFile.cpp
index a9b46c7a77d..c8d45a88f6a 100644
--- a/Libraries/LibCore/MappedFile.cpp
+++ b/Libraries/LibCore/MappedFile.cpp
@@ -9,9 +9,7 @@
 #include <LibCore/File.h>
 #include <LibCore/MappedFile.h>
 #include <LibCore/System.h>
-#include <fcntl.h>
 #include <sys/mman.h>
-#include <unistd.h>
 
 namespace Core {
 
@@ -29,10 +27,8 @@ ErrorOr<NonnullOwnPtr<MappedFile>> MappedFile::map_from_file(NonnullOwnPtr<Core:
 
 ErrorOr<NonnullOwnPtr<MappedFile>> MappedFile::map_from_fd_and_close(int fd, [[maybe_unused]] StringView path, Mode mode)
 {
-    TRY(Core::System::fcntl(fd, F_SETFD, FD_CLOEXEC));
-
     ScopeGuard fd_close_guard = [fd] {
-        ::close(fd);
+        (void)System::close(fd);
     };
 
     auto stat = TRY(Core::System::fstat(fd));
diff --git a/Libraries/LibCore/SystemWindows.cpp b/Libraries/LibCore/SystemWindows.cpp
index 9587ec9d10f..c4fe2ed1444 100644
--- a/Libraries/LibCore/SystemWindows.cpp
+++ b/Libraries/LibCore/SystemWindows.cpp
@@ -15,6 +15,7 @@
 #include <Windows.h>
 #include <direct.h>
 #include <io.h>
+#include <sys/mman.h>
 
 namespace Core::System {
 
@@ -166,4 +167,21 @@ ErrorOr<struct stat> fstatat(int, StringView, int)
     VERIFY_NOT_REACHED();
 }
 
+ErrorOr<void*> mmap(void* address, size_t size, int protection, int flags, int fd, off_t offset, size_t alignment, StringView)
+{
+    // custom alignment is not supported
+    VERIFY(!alignment);
+    void* ptr = ::mmap(address, size, protection, flags, fd, offset);
+    if (ptr == MAP_FAILED)
+        return Error::from_syscall("mmap"sv, -errno);
+    return ptr;
+}
+
+ErrorOr<void> munmap(void* address, size_t size)
+{
+    if (::munmap(address, size) < 0)
+        return Error::from_syscall("munmap"sv, -errno);
+    return {};
+}
+
 }
diff --git a/Meta/CMake/Findmman.cmake b/Meta/CMake/Findmman.cmake
new file mode 100644
index 00000000000..ea6ab5aa2c0
--- /dev/null
+++ b/Meta/CMake/Findmman.cmake
@@ -0,0 +1,2 @@
+find_path(MMAN_INCLUDE_DIR sys/mman.h PATH_SUFFIXES mman)
+find_library(MMAN_LIBRARY mman)
diff --git a/vcpkg.json b/vcpkg.json
index cab66098657..86d8ab31136 100644
--- a/vcpkg.json
+++ b/vcpkg.json
@@ -71,6 +71,10 @@
         "simd"
       ]
     },
+    {
+      "name": "mman",
+      "platform": "windows"
+    },
     "simdutf",
     {
       "name": "skia",