diff --git a/Kernel/API/POSIX/futex.h b/Kernel/API/POSIX/futex.h
new file mode 100644
index 0000000000..74f030c866
--- /dev/null
+++ b/Kernel/API/POSIX/futex.h
@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <Kernel/API/POSIX/sys/types.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define _FUTEX_OP_SHIFT_OP 28
+#define _FUTEX_OP_MASK_OP 0xf
+#define _FUTEX_OP_SHIFT_CMP 24
+#define _FUTEX_OP_MASK_CMP 0xf
+#define _FUTEX_OP_SHIFT_OP_ARG 12
+#define _FUTEX_OP_MASK_OP_ARG 0xfff
+#define _FUTEX_OP_SHIFT_CMP_ARG 0
+#define _FUTEX_OP_MASK_CMP_ARG 0xfff
+
+#define FUTEX_OP(op, op_arg, cmp, cmp_arg) \
+    ((((op)&_FUTEX_OP_MASK_OP) << _FUTEX_OP_SHIFT_OP) | (((cmp)&_FUTEX_OP_MASK_CMP) << _FUTEX_OP_SHIFT_CMP) | (((op_arg)&_FUTEX_OP_MASK_OP_ARG) << _FUTEX_OP_SHIFT_OP_ARG) | (((cmp_arg)&_FUTEX_OP_MASK_CMP_ARG) << _FUTEX_OP_SHIFT_CMP_ARG))
+
+#define _FUTEX_OP(val3) (((val3) >> _FUTEX_OP_SHIFT_OP) & _FUTEX_OP_MASK_OP)
+#define _FUTEX_CMP(val3) (((val3) >> _FUTEX_OP_SHIFT_CMP) & _FUTEX_OP_MASK_CMP)
+#define _FUTEX_OP_ARG(val3) (((val3) >> _FUTEX_OP_SHIFT_OP_ARG) & _FUTEX_OP_MASK_OP_ARG)
+#define _FUTEX_CMP_ARG(val3) (((val3) >> _FUTEX_OP_SHIFT_CMP_ARG) & _FUTEX_OP_MASK_CMP_ARG)
+
+#define FUTEX_OP_SET 0
+#define FUTEX_OP_ADD 1
+#define FUTEX_OP_OR 2
+#define FUTEX_OP_ANDN 3
+#define FUTEX_OP_XOR 4
+#define FUTEX_OP_ARG_SHIFT 8
+
+#define FUTEX_OP_CMP_EQ 0
+#define FUTEX_OP_CMP_NE 1
+#define FUTEX_OP_CMP_LT 2
+#define FUTEX_OP_CMP_LE 3
+#define FUTEX_OP_CMP_GT 4
+#define FUTEX_OP_CMP_GE 5
+
+#define FUTEX_WAIT 1
+#define FUTEX_WAKE 2
+
+#define FUTEX_REQUEUE 3
+#define FUTEX_CMP_REQUEUE 4
+#define FUTEX_WAKE_OP 5
+#define FUTEX_WAIT_BITSET 9
+#define FUTEX_WAKE_BITSET 10
+
+#define FUTEX_PRIVATE_FLAG (1 << 7)
+#define FUTEX_CLOCK_REALTIME (1 << 8)
+#define FUTEX_CMD_MASK ~(FUTEX_PRIVATE_FLAG | FUTEX_CLOCK_REALTIME)
+
+#define FUTEX_BITSET_MATCH_ANY 0xffffffff
+
+#ifdef __cplusplus
+}
+#endif
diff --git a/Kernel/UnixTypes.h b/Kernel/UnixTypes.h
index c8337a82e6..414e08296a 100644
--- a/Kernel/UnixTypes.h
+++ b/Kernel/UnixTypes.h
@@ -9,6 +9,7 @@
 #include <AK/DistinctNumeric.h>
 #include <AK/Types.h>
 #include <Kernel/API/POSIX/fcntl.h>
+#include <Kernel/API/POSIX/futex.h>
 #include <Kernel/API/POSIX/netinet/in.h>
 #include <Kernel/API/POSIX/signal.h>
 #include <Kernel/API/POSIX/sys/mman.h>
@@ -90,48 +91,6 @@ enum {
 
 #define FD_CLOEXEC 1
 
-#define _FUTEX_OP_SHIFT_OP 28
-#define _FUTEX_OP_MASK_OP 0xf
-#define _FUTEX_OP_SHIFT_CMP 24
-#define _FUTEX_OP_MASK_CMP 0xf
-#define _FUTEX_OP_SHIFT_OP_ARG 12
-#define _FUTEX_OP_MASK_OP_ARG 0xfff
-#define _FUTEX_OP_SHIFT_CMP_ARG 0
-#define _FUTEX_OP_MASK_CMP_ARG 0xfff
-
-#define _FUTEX_OP(val3) (((val3) >> _FUTEX_OP_SHIFT_OP) & _FUTEX_OP_MASK_OP)
-#define _FUTEX_CMP(val3) (((val3) >> _FUTEX_OP_SHIFT_CMP) & _FUTEX_OP_MASK_CMP)
-#define _FUTEX_OP_ARG(val3) (((val3) >> _FUTEX_OP_SHIFT_OP_ARG) & _FUTEX_OP_MASK_OP_ARG)
-#define _FUTEX_CMP_ARG(val3) (((val3) >> _FUTEX_OP_SHIFT_CMP_ARG) & _FUTEX_OP_MASK_CMP_ARG)
-
-#define FUTEX_OP_SET 0
-#define FUTEX_OP_ADD 1
-#define FUTEX_OP_OR 2
-#define FUTEX_OP_ANDN 3
-#define FUTEX_OP_XOR 4
-#define FUTEX_OP_ARG_SHIFT 8
-
-#define FUTEX_OP_CMP_EQ 0
-#define FUTEX_OP_CMP_NE 1
-#define FUTEX_OP_CMP_LT 2
-#define FUTEX_OP_CMP_LE 3
-#define FUTEX_OP_CMP_GT 4
-#define FUTEX_OP_CMP_GE 5
-
-#define FUTEX_WAIT 1
-#define FUTEX_WAKE 2
-#define FUTEX_REQUEUE 3
-#define FUTEX_CMP_REQUEUE 4
-#define FUTEX_WAKE_OP 5
-#define FUTEX_WAIT_BITSET 9
-#define FUTEX_WAKE_BITSET 10
-
-#define FUTEX_PRIVATE_FLAG (1 << 7)
-#define FUTEX_CLOCK_REALTIME (1 << 8)
-#define FUTEX_CMD_MASK ~(FUTEX_PRIVATE_FLAG | FUTEX_CLOCK_REALTIME)
-
-#define FUTEX_BITSET_MATCH_ANY 0xffffffff
-
 // Avoid interference with AK/Types.h and LibC/sys/types.h by defining *separate* names:
 TYPEDEF_DISTINCT_ORDERED_ID(pid_t, ProcessID);
 TYPEDEF_DISTINCT_ORDERED_ID(pid_t, ThreadID);
diff --git a/Userland/Libraries/LibC/serenity.h b/Userland/Libraries/LibC/serenity.h
index 3919c911d2..7f81f92f04 100644
--- a/Userland/Libraries/LibC/serenity.h
+++ b/Userland/Libraries/LibC/serenity.h
@@ -6,6 +6,7 @@
 
 #pragma once
 
+#include <Kernel/API/POSIX/futex.h>
 #include <stdio.h>
 #include <sys/cdefs.h>
 #include <sys/types.h>
@@ -29,47 +30,6 @@ int profiling_free_buffer(pid_t);
 #define THREAD_PRIORITY_HIGH 50
 #define THREAD_PRIORITY_MAX 99
 
-#define _FUTEX_OP_SHIFT_OP 28
-#define _FUTEX_OP_MASK_OP 0xf
-#define _FUTEX_OP_SHIFT_CMP 24
-#define _FUTEX_OP_MASK_CMP 0xf
-#define _FUTEX_OP_SHIFT_OP_ARG 12
-#define _FUTEX_OP_MASK_OP_ARG 0xfff
-#define _FUTEX_OP_SHIFT_CMP_ARG 0
-#define _FUTEX_OP_MASK_CMP_ARG 0xfff
-
-#define FUTEX_OP(op, op_arg, cmp, cmp_arg) \
-    ((((op)&_FUTEX_OP_MASK_OP) << _FUTEX_OP_SHIFT_OP) | (((cmp)&_FUTEX_OP_MASK_CMP) << _FUTEX_OP_SHIFT_CMP) | (((op_arg)&_FUTEX_OP_MASK_OP_ARG) << _FUTEX_OP_SHIFT_OP_ARG) | (((cmp_arg)&_FUTEX_OP_MASK_CMP_ARG) << _FUTEX_OP_SHIFT_CMP_ARG))
-
-#define FUTEX_OP_SET 0
-#define FUTEX_OP_ADD 1
-#define FUTEX_OP_OR 2
-#define FUTEX_OP_ANDN 3
-#define FUTEX_OP_XOR 4
-#define FUTEX_OP_ARG_SHIFT 8
-
-#define FUTEX_OP_CMP_EQ 0
-#define FUTEX_OP_CMP_NE 1
-#define FUTEX_OP_CMP_LT 2
-#define FUTEX_OP_CMP_LE 3
-#define FUTEX_OP_CMP_GT 4
-#define FUTEX_OP_CMP_GE 5
-
-#define FUTEX_WAIT 1
-#define FUTEX_WAKE 2
-
-#define FUTEX_REQUEUE 3
-#define FUTEX_CMP_REQUEUE 4
-#define FUTEX_WAKE_OP 5
-#define FUTEX_WAIT_BITSET 9
-#define FUTEX_WAKE_BITSET 10
-
-#define FUTEX_PRIVATE_FLAG (1 << 7)
-#define FUTEX_CLOCK_REALTIME (1 << 8)
-#define FUTEX_CMD_MASK ~(FUTEX_PRIVATE_FLAG | FUTEX_CLOCK_REALTIME)
-
-#define FUTEX_BITSET_MATCH_ANY 0xffffffff
-
 int futex(uint32_t* userspace_address, int futex_op, uint32_t value, const struct timespec* timeout, uint32_t* userspace_address2, uint32_t value3);
 
 static ALWAYS_INLINE int futex_wait(uint32_t* userspace_address, uint32_t value, const struct timespec* abstime, int clockid)