diff --git a/core/include/lifo.h b/core/include/lifo.h
deleted file mode 100644
index bcf723cc69..0000000000
--- a/core/include/lifo.h
+++ /dev/null
@@ -1,128 +0,0 @@
-/*
- * Copyright (C) 2013 Freie Universität Berlin
- *
- * This file is subject to the terms and conditions of the GNU Lesser
- * General Public License v2.1. See the file LICENSE in the top level
- * directory for more details.
- */
-
-/**
- * @ingroup     core_util
- * @{
- *
- * @file
- * @brief   LIFO buffer API, read long description carefully
- * @author  Heiko Will <hwill@inf.fu-berlin.de>
- * @deprecated Is no longer used in RIOT.
- *             Has very tight constrains making new use unlikely.
- *             Will be removed after release 2021.04.
- *
- * @details This LIFO implementation very efficiently handles integer values.
- *          The caveat is that it **can only handle values between 0 and its own
- *          size - 1**. Also it can only handle up to one element of each value.
- *          If you insert a value twice the LIFO will break.
- */
-
-#ifndef LIFO_H
-#define LIFO_H
-
-#include "log.h"
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/**
- * @brief   Check if the given lifo is empty.
- *
- * @param[in] array The lifo array to check.
- *
- * @return  1, if empty
- * @return  0, otherwise.
- */
-static inline int lifo_empty(int *array)
-{
-    return array[0] == -1;
-}
-
-/**
- * @brief               Initialize a lifo array.
- *
- * @pre `array != NULL`
- *
- * @param[in,out] array An array of size *n* + 1. Must not be `NULL`.
- * @param[in] n         Maximum integer value the lifo is able to store.
- */
-static inline void lifo_init(int *array, int n)
-{
-    LOG_DEBUG("lifo_init(%i)\n", n);
-    for (int i = 0; i <= n; i++) {
-        array[i] = -1;
-    }
-}
-
-/**
- * @brief               Insert an element into the lifo
- *
- * @pre `array != NULL`
- *
- * @param[in,out] array An integer array of least *i* + 1 size that **does not
- *                      already contain *i***. Must not be `NULL`.
- * @param[in] i         The integer value to store, between 0 and the size of
- *                      the array - 1, must not be stored already.
- *
- */
-static inline void lifo_insert(int *array, int i)
-{
-    LOG_DEBUG("lifo_insert(%i)\n", i);
-
-    int index = i + 1;
-
-#ifdef DEVELHELP
-    if ((array[index] != -1) && (array[0] != -1)) {
-        LOG_WARNING(
-            "lifo_insert: overwriting array[%i] == %i with %i\n\n\n"
-            "\t\tThe lifo is broken now.\n\n\n", index,
-            array[index], array[0]);
-    }
-#endif
-
-    array[index] = array[0];
-    array[0] = i;
-}
-
-/**
- * @brief           Extract the least recently inserted element from the lifo.
- *
- * @pre `array != NULL`
- *
- * @param[in] array An integer array. Must not be NULL.
- *
- * @return          -1, if the lifo is empty.
- * @return          the least recently inserted element, otherwise.
- */
-static inline int lifo_get(int *array)
-{
-    LOG_DEBUG("lifo_get\n");
-    int head = array[0];
-
-    if (head != -1) {
-        array[0] = array[head + 1];
-    }
-
-#ifdef DEVELHELP
-    /* make sure a double insert does not result in an infinite
-     * resource of values */
-    array[head + 1] = -1;
-#endif
-
-    LOG_DEBUG("lifo_get: returning %i\n", head);
-    return head;
-}
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* LIFO_H */
-/** @} */