diff --git a/build-aux/configure-lib.sh b/build-aux/configure-lib.sh
index 159aa11b..6871ab8e 100644
--- a/build-aux/configure-lib.sh
+++ b/build-aux/configure-lib.sh
@@ -29,47 +29,60 @@ fi
 
 . ./config.sh
 
-libc_mini_SOURCES="
+libc_mini_shared_SOURCES="
 lib/mes/eputs.c
 lib/mes/oputs.c
 "
 
 if test $mes_libc = mes; then
-    libc_mini_SOURCES="$libc_mini_SOURCES
-lib/posix/write.c
-lib/string/strlen.c
-lib/stdlib/puts.c
-lib/stdlib/exit.c
+    libc_mini_shared_SOURCES="$libc_mini_shared_SOURCES
 lib/$mes_kernel/$mes_cpu-mes-$compiler/mini.c
+lib/stdlib/exit.c
+lib/stdlib/puts.c
+lib/string/strlen.c
+"
+fi
+
+libc_mini_SOURCES="$libc_mini_shared_SOURCES"
+
+if test $mes_libc = mes; then
+    libc_mini_SOURCES="$libc_mini_SOURCES
+lib/mes/write.c
 "
 fi
 
 libmes_SOURCES="
-$libc_mini_SOURCES
+$libc_mini_shared_SOURCES
 lib/ctype/isnumber.c
 lib/mes/abtol.c
-lib/mes/itoa.c
-lib/mes/ltoa.c
-lib/mes/ltoab.c
-lib/mes/ultoa.c
-lib/mes/utoa.c
 lib/mes/eputc.c
 lib/mes/fdgetc.c
 lib/mes/fdputc.c
 lib/mes/fdputs.c
 lib/mes/fdungetc.c
+lib/mes/itoa.c
+lib/mes/ltoa.c
+lib/mes/ltoab.c
 lib/mes/mes_open.c
 lib/mes/ntoab.c
 lib/mes/oputc.c
+lib/mes/ultoa.c
+lib/mes/utoa.c
 "
 
 if test $mes_libc = mes; then
     libmes_SOURCES="$libmes_SOURCES
-lib/stdlib/atoi.c
 lib/ctype/isdigit.c
 lib/ctype/isspace.c
 lib/ctype/isxdigit.c
+lib/posix/write.c
+lib/stdlib/atoi.c
 "
+    if test $mes_kernel = linux; then
+        libmes_SOURCES="$libmes_SOURCES
+lib/linux/lseek.c
+"
+    fi
 else
     libmes_SOURCES="$libmes_SOURCES
 "
@@ -192,7 +205,6 @@ lib/$mes_cpu-mes-$compiler/setjmp.c
 if test $mes_kernel = linux; then
     libc_tcc_SOURCES="$libc_tcc_SOURCES
 lib/linux/close.c
-lib/linux/lseek.c
 lib/linux/rmdir.c
 lib/linux/stat.c
 "
diff --git a/lib/mes/write.c b/lib/mes/write.c
new file mode 100644
index 00000000..30344cad
--- /dev/null
+++ b/lib/mes/write.c
@@ -0,0 +1,36 @@
+/* -*-comment-start: "//";comment-end:""-*-
+ * GNU Mes --- Maxwell Equations of Software
+ * Copyright © 2016,2017,2018,2019 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
+ *
+ * This file is part of GNU Mes.
+ *
+ * GNU Mes is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or (at
+ * your option) any later version.
+ *
+ * GNU Mes is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU Mes.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <mes/lib.h>
+#include <errno.h>
+
+ssize_t
+write (int filedes, void const *buffer, size_t size)
+{
+  int r = _write (filedes, buffer, size);
+  if (r < 0)
+    {
+      errno = -r;
+      r = -1;
+    }
+  else
+    errno = 0;
+  return r;
+}
diff --git a/lib/posix/write.c b/lib/posix/write.c
index 6843cd55..c36b2a1c 100644
--- a/lib/posix/write.c
+++ b/lib/posix/write.c
@@ -18,21 +18,17 @@
  * along with GNU Mes.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include <mes/lib-mini.h>
+#include <mes/lib.h>
 #include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
 
 ssize_t
 write (int filedes, void const *buffer, size_t size)
 {
-#if 0 // !MES_MINI
-  // FIXME: libc-mini has no __buffered_read_clear, lseek.
-  // and libc includes libc-mini...how to override?
-  // Let's hope everyone uses fwrite, or lseek for RDWR
-  // semantics...
   size_t skip = __buffered_read_clear (filedes);
   if (skip)
     lseek (filedes, -skip, SEEK_CUR);
-#endif
   int r = _write (filedes, buffer, size);
   if (r < 0)
     {
diff --git a/lib/stdio/fwrite.c b/lib/stdio/fwrite.c
index 6e048ee2..2e2030bd 100644
--- a/lib/stdio/fwrite.c
+++ b/lib/stdio/fwrite.c
@@ -36,11 +36,7 @@ fwrite (void const *data, size_t size, size_t count, FILE * stream)
 
   if (!size || !count)
     return 0;
-  // FIXME: should be in write, but that's libc-mini.
   int filedes = (long) stream;
-  size_t skip = __buffered_read_clear (filedes);
-  if (skip)
-    lseek (filedes, -skip, SEEK_CUR);
   int bytes = write (filedes, data, size * count);
 
   if (__mes_debug () > 2)
diff --git a/simple.sh b/simple.sh
index 97e249e6..5107f7b4 100755
--- a/simple.sh
+++ b/simple.sh
@@ -93,7 +93,7 @@ MES_DEBUG=2 MES=out-system-libc/mes sh -x scripts/mescc -m $mes_bits -nostdlib\
          \
          lib/linux/$mes_cpu-mes-mescc/mini.c\
          \
-         lib/posix/write.c\
+         lib/mes/write.c\
          lib/string/strlen.c\
          \
          scaffold/hello.c
@@ -197,6 +197,8 @@ $CC -g -D HAVE_CONFIG_H=1 -I include -I include/$mes_kernel/$mes_cpu\
     lib/string/strcpy.c\
     lib/string/strncmp.c\
     \
+    lib/linux/lseek.c\
+    \
     lib/linux/access.c\
     lib/linux/brk.c\
     lib/linux/chmod.c\
@@ -252,7 +254,7 @@ MES_DEBUG=2 MES=out-mes/mes sh -x scripts/mescc -m $mes_bits -nostdlib\
          \
          lib/linux/$mes_cpu-mes-mescc/mini.c\
          \
-         lib/posix/write.c\
+         lib/mes/write.c\
          lib/string/strlen.c\
          \
          scaffold/hello.c