diff --git a/cpu/avr8_common/Kconfig b/cpu/avr8_common/Kconfig
index e982adc423..54bd222d82 100644
--- a/cpu/avr8_common/Kconfig
+++ b/cpu/avr8_common/Kconfig
@@ -12,6 +12,7 @@ config CPU_ARCH_AVR8
     select HAS_ARCH_AVR8
 
     select MODULE_MALLOC_THREAD_SAFE if TEST_KCONFIG
+    select MODULE_TINY_STRERROR_AS_STRERROR if TEST_KCONFIG
     # static C++ constructors need guards for thread safe initialization
     select MODULE_CXX_CTOR_GUARDS if MODULE_CPP
     # new and delete operators needed
diff --git a/cpu/avr8_common/Makefile.dep b/cpu/avr8_common/Makefile.dep
index 8a35c0ac99..6f0042d7b1 100644
--- a/cpu/avr8_common/Makefile.dep
+++ b/cpu/avr8_common/Makefile.dep
@@ -9,6 +9,9 @@ USEMODULE += avr8_common
 # instead.
 USEMODULE += malloc_thread_safe
 
+# The AVR-libc provides no strerror, so we provide it via tiny_strerror
+USEMODULE += tiny_strerror_as_strerror
+
 # the atmel port uses stdio_uart by default
 ifeq (,$(filter stdio_% slipdev_stdio,$(USEMODULE)))
   USEMODULE += stdio_uart
diff --git a/cpu/avr8_common/avr_libc_extra/posix_unistd.c b/cpu/avr8_common/avr_libc_extra/posix_unistd.c
index 93c6d67fda..05aa350997 100644
--- a/cpu/avr8_common/avr_libc_extra/posix_unistd.c
+++ b/cpu/avr8_common/avr_libc_extra/posix_unistd.c
@@ -177,80 +177,4 @@ ssize_t write(int fd, const void *src, size_t count)
 #endif
 }
 
-const char *strerror(int errnum)
-{
-    if (errnum < 0) {
-        errnum = -errnum;
-    }
-
-    switch (errnum) {
-        case 0: return "OK";
-        case EDOM: return "EDOM";
-        case ERANGE: return "ERANGE";
-        case ENOSYS: return "ENOSYS";
-        case EINTR: return "EINTR";
-        case E2BIG: return "E2BIG";
-        case EACCES: return "EACCES";
-        case EADDRINUSE: return "EADDRINUSE";
-        case EADDRNOTAVAIL: return "EADDRNOTAVAIL";
-        case EAFNOSUPPORT: return "EAFNOSUPPORT";
-        case EAGAIN: return "EAGAIN";
-        case EALREADY: return "EALREADY";
-        case EBADF: return "EBADF";
-        case EBUSY: return "EBUSY";
-        case ECHILD: return "ECHILD";
-        case ECONNABORTED: return "ECONNABORTED";
-        case ECONNREFUSED: return "ECONNREFUSED";
-        case ECONNRESET: return "ECONNRESET";
-        case EDEADLK: return "EDEADLK";
-        case EDESTADDRREQ: return "EDESTADDRREQ";
-        case EEXIST: return "EEXIST";
-        case EFAULT: return "EFAULT";
-        case EFBIG: return "EFBIG";
-        case EHOSTUNREACH: return "EHOSTUNREACH";
-        case EILSEQ: return "EILSEQ";
-        case EINPROGRESS: return "EINPROGRESS";
-        case EINVAL: return "EINVAL";
-        case EIO: return "EIO";
-        case EISCONN: return "EISCONN";
-        case EISDIR: return "EISDIR";
-        case ELOOP: return "ELOOP";
-        case EMFILE: return "EMFILE";
-        case EMLINK: return "EMLINK";
-        case EMSGSIZE: return "EMSGSIZE";
-        case ENAMETOOLONG: return "ENAMETOOLONG";
-        case ENETDOWN: return "ENETDOWN";
-        case ENETRESET: return "ENETRESET";
-        case ENETUNREACH: return "ENETUNREACH";
-        case ENFILE: return "ENFILE";
-        case ENOBUFS: return "ENOBUFS";
-        case ENODEV: return "ENODEV";
-        case ENOENT: return "ENOENT";
-        case ENOEXEC: return "ENOEXEC";
-        case ENOLCK: return "ENOLCK";
-        case ENOMEM: return "ENOMEM";
-        case ENOMSG: return "ENOMSG";
-        case ENOPROTOOPT: return "ENOPROTOOPT";
-        case ENOSPC: return "ENOSPC";
-        case ENOTCONN: return "ENOTCONN";
-        case ENOTDIR: return "ENOTDIR";
-        case ENOTEMPTY: return "ENOTEMPTY";
-        case ENOTSOCK: return "ENOTSOCK";
-        case ENOTTY: return "ENOTTY";
-        case ENXIO: return "ENXIO";
-        case EOPNOTSUPP: return "EOPNOTSUPP";
-        case EPERM: return "EPERM";
-        case EPIPE: return "EPIPE";
-        case EPROTONOSUPPORT: return "EPROTONOSUPPORT";
-        case EPROTOTYPE: return "EPROTOTYPE";
-        case EROFS: return "EROFS";
-        case ESPIPE: return "ESPIPE";
-        case ESRCH: return "ESRCH";
-        case ETIMEDOUT: return "ETIMEDOUT";
-        case EWOULDBLOCK: return "EWOULDBLOCK";
-        case EXDEV: return "EXDEV";
-        default: return "unknown";
-    }
-}
-
 /** @} */