diff --git a/Tests/Kernel/fuzz-syscalls.cpp b/Tests/Kernel/fuzz-syscalls.cpp
index 6a945a06f64..9e160142528 100644
--- a/Tests/Kernel/fuzz-syscalls.cpp
+++ b/Tests/Kernel/fuzz-syscalls.cpp
@@ -10,11 +10,11 @@
 #include <AK/StringBuilder.h>
 #include <AK/Vector.h>
 #include <errno.h>
-#include <mman.h>
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/mman.h>
 #include <syscall.h>
 
 static bool is_deadly_syscall(int fn)
diff --git a/Tests/LibC/TestLibCMkTemp.cpp b/Tests/LibC/TestLibCMkTemp.cpp
index 85bdb034202..5045640a869 100644
--- a/Tests/LibC/TestLibCMkTemp.cpp
+++ b/Tests/LibC/TestLibCMkTemp.cpp
@@ -9,10 +9,10 @@
 #include <LibCore/File.h>
 #include <LibTest/TestCase.h>
 #include <fcntl.h>
-#include <mman.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/mman.h>
 #include <sys/wait.h>
 #include <unistd.h>
 
diff --git a/Tests/UserspaceEmulator/write-oob.cpp b/Tests/UserspaceEmulator/write-oob.cpp
index 77620a71050..811d7199ec3 100644
--- a/Tests/UserspaceEmulator/write-oob.cpp
+++ b/Tests/UserspaceEmulator/write-oob.cpp
@@ -6,10 +6,10 @@
 
 #include <AK/Assertions.h>
 #include <LibCore/ArgsParser.h>
-#include <mman.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <sys/mman.h>
 
 static void write8(void* ptr) { *(volatile uint8_t*)ptr = 1; }
 static void write16(void* ptr) { *(volatile uint16_t*)ptr = 1; }
diff --git a/Userland/Libraries/LibC/CMakeLists.txt b/Userland/Libraries/LibC/CMakeLists.txt
index 2a43b51aa54..44f7e46bcc8 100644
--- a/Userland/Libraries/LibC/CMakeLists.txt
+++ b/Userland/Libraries/LibC/CMakeLists.txt
@@ -16,7 +16,6 @@ set(LIBC_SOURCES
     link.cpp
     locale.cpp
     malloc.cpp
-    mman.cpp
     mntent.cpp
     net.cpp
     netdb.cpp
@@ -40,6 +39,7 @@ set(LIBC_SOURCES
     strings.cpp
     stubs.cpp
     syslog.cpp
+    sys/mman.cpp
     sys/prctl.cpp
     sys/ptrace.cpp
     sys/select.cpp
diff --git a/Userland/Libraries/LibC/mman.h b/Userland/Libraries/LibC/mman.h
deleted file mode 100644
index d2638bd03f4..00000000000
--- a/Userland/Libraries/LibC/mman.h
+++ /dev/null
@@ -1,45 +0,0 @@
-/*
- * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
- *
- * SPDX-License-Identifier: BSD-2-Clause
- */
-
-#pragma once
-
-#include <sys/cdefs.h>
-#include <sys/types.h>
-
-#define MAP_FILE 0x00
-#define MAP_SHARED 0x01
-#define MAP_PRIVATE 0x02
-#define MAP_FIXED 0x10
-#define MAP_ANONYMOUS 0x20
-#define MAP_ANON MAP_ANONYMOUS
-#define MAP_STACK 0x40
-#define MAP_NORESERVE 0x80
-#define MAP_RANDOMIZED 0x100
-
-#define PROT_READ 0x1
-#define PROT_WRITE 0x2
-#define PROT_EXEC 0x4
-#define PROT_NONE 0x0
-
-#define MAP_FAILED ((void*)-1)
-
-#define MADV_SET_VOLATILE 0x100
-#define MADV_SET_NONVOLATILE 0x200
-#define MADV_GET_VOLATILE 0x400
-
-__BEGIN_DECLS
-
-void* mmap(void* addr, size_t, int prot, int flags, int fd, off_t);
-void* mmap_with_name(void* addr, size_t, int prot, int flags, int fd, off_t, const char* name);
-void* serenity_mmap(void* addr, size_t, int prot, int flags, int fd, off_t, size_t alignment, const char* name);
-void* mremap(void* old_address, size_t old_size, size_t new_size, int flags);
-int munmap(void*, size_t);
-int mprotect(void*, size_t, int prot);
-int set_mmap_name(void*, size_t, const char*);
-int madvise(void*, size_t, int advice);
-void* allocate_tls(const char* initial_data, size_t);
-
-__END_DECLS
diff --git a/Userland/Libraries/LibC/mman.cpp b/Userland/Libraries/LibC/sys/mman.cpp
similarity index 99%
rename from Userland/Libraries/LibC/mman.cpp
rename to Userland/Libraries/LibC/sys/mman.cpp
index c78f524b717..101860fafcb 100644
--- a/Userland/Libraries/LibC/mman.cpp
+++ b/Userland/Libraries/LibC/sys/mman.cpp
@@ -5,9 +5,9 @@
  */
 
 #include <errno.h>
-#include <mman.h>
 #include <stdio.h>
 #include <string.h>
+#include <sys/mman.h>
 #include <syscall.h>
 
 extern "C" {
diff --git a/Userland/Libraries/LibC/sys/mman.h b/Userland/Libraries/LibC/sys/mman.h
index fbaaf7952f5..d2638bd03f4 100644
--- a/Userland/Libraries/LibC/sys/mman.h
+++ b/Userland/Libraries/LibC/sys/mman.h
@@ -6,4 +6,40 @@
 
 #pragma once
 
-#include <mman.h>
+#include <sys/cdefs.h>
+#include <sys/types.h>
+
+#define MAP_FILE 0x00
+#define MAP_SHARED 0x01
+#define MAP_PRIVATE 0x02
+#define MAP_FIXED 0x10
+#define MAP_ANONYMOUS 0x20
+#define MAP_ANON MAP_ANONYMOUS
+#define MAP_STACK 0x40
+#define MAP_NORESERVE 0x80
+#define MAP_RANDOMIZED 0x100
+
+#define PROT_READ 0x1
+#define PROT_WRITE 0x2
+#define PROT_EXEC 0x4
+#define PROT_NONE 0x0
+
+#define MAP_FAILED ((void*)-1)
+
+#define MADV_SET_VOLATILE 0x100
+#define MADV_SET_NONVOLATILE 0x200
+#define MADV_GET_VOLATILE 0x400
+
+__BEGIN_DECLS
+
+void* mmap(void* addr, size_t, int prot, int flags, int fd, off_t);
+void* mmap_with_name(void* addr, size_t, int prot, int flags, int fd, off_t, const char* name);
+void* serenity_mmap(void* addr, size_t, int prot, int flags, int fd, off_t, size_t alignment, const char* name);
+void* mremap(void* old_address, size_t old_size, size_t new_size, int flags);
+int munmap(void*, size_t);
+int mprotect(void*, size_t, int prot);
+int set_mmap_name(void*, size_t, const char*);
+int madvise(void*, size_t, int advice);
+void* allocate_tls(const char* initial_data, size_t);
+
+__END_DECLS
diff --git a/Userland/Libraries/LibELF/DynamicLinker.cpp b/Userland/Libraries/LibELF/DynamicLinker.cpp
index 6551d9db55b..37281ad9716 100644
--- a/Userland/Libraries/LibELF/DynamicLinker.cpp
+++ b/Userland/Libraries/LibELF/DynamicLinker.cpp
@@ -16,7 +16,7 @@
 #include <AK/Vector.h>
 #include <LibC/bits/pthread_integration.h>
 #include <LibC/link.h>
-#include <LibC/mman.h>
+#include <LibC/sys/mman.h>
 #include <LibC/unistd.h>
 #include <LibDl/dlfcn.h>
 #include <LibDl/dlfcn_integration.h>
diff --git a/Userland/Utilities/syscall.cpp b/Userland/Utilities/syscall.cpp
index e9a160a9262..86aea17ad65 100644
--- a/Userland/Utilities/syscall.cpp
+++ b/Userland/Utilities/syscall.cpp
@@ -8,10 +8,10 @@
 #include <AK/Iterator.h>
 #include <AK/Vector.h>
 #include <LibCore/ArgsParser.h>
-#include <mman.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/mman.h>
 #include <syscall.h>
 
 #define SC_NARG 4
diff --git a/Userland/Utilities/tt.cpp b/Userland/Utilities/tt.cpp
index 599425ee57a..3f5dbc4e3e4 100644
--- a/Userland/Utilities/tt.cpp
+++ b/Userland/Utilities/tt.cpp
@@ -6,11 +6,11 @@
 
 #include <LibCore/ArgsParser.h>
 #include <errno.h>
-#include <mman.h>
 #include <pthread.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/mman.h>
 #include <unistd.h>
 
 static int mutex_test();