diff --git a/gdb/ada-typeprint.c b/gdb/ada-typeprint.c
index a43ced7..305e39c 100644
--- a/gdb/ada-typeprint.c
+++ b/gdb/ada-typeprint.c
@@ -32,9 +32,7 @@
 #include "c-lang.h"
 #include "typeprint.h"
 #include "ada-lang.h"
-
 #include <ctype.h>
-#include <errno.h>
 
 static int print_selected_record_field_types (struct type *, struct type *,
 					      int, int,
diff --git a/gdb/c-typeprint.c b/gdb/c-typeprint.c
index 5239505..374c90e 100644
--- a/gdb/c-typeprint.c
+++ b/gdb/c-typeprint.c
@@ -31,7 +31,6 @@
 #include "typeprint.h"
 #include "cp-abi.h"
 #include "jv-lang.h"
-#include <errno.h>
 #include "cp-support.h"
 
 static void c_type_print_varspec_prefix (struct type *,
diff --git a/gdb/common/common-defs.h b/gdb/common/common-defs.h
index 7c67846..82290dc 100644
--- a/gdb/common/common-defs.h
+++ b/gdb/common/common-defs.h
@@ -32,6 +32,7 @@
 #include <stdarg.h>
 #include <stddef.h>
 #include <string.h>
+#include <errno.h>
 #include "ansidecl.h"
 #include "libiberty.h"
 #include "pathmax.h"
diff --git a/gdb/core-regset.c b/gdb/core-regset.c
index 6edc8c5..bdcb72a 100644
--- a/gdb/core-regset.c
+++ b/gdb/core-regset.c
@@ -34,7 +34,6 @@
 #include "regcache.h"
 
 #include <fcntl.h>
-#include <errno.h>
 #include <time.h>
 #ifdef HAVE_SYS_PROCFS_H
 #include <sys/procfs.h>
diff --git a/gdb/corefile.c b/gdb/corefile.c
index 983caa9..1617392 100644
--- a/gdb/corefile.c
+++ b/gdb/corefile.c
@@ -18,7 +18,6 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include "defs.h"
-#include <errno.h>
 #include <signal.h>
 #include <fcntl.h>
 #include "inferior.h"
diff --git a/gdb/corelow.c b/gdb/corelow.c
index ee0f655..ff4d733 100644
--- a/gdb/corelow.c
+++ b/gdb/corelow.c
@@ -19,7 +19,6 @@
 
 #include "defs.h"
 #include "arch-utils.h"
-#include <errno.h>
 #include <signal.h>
 #include <fcntl.h>
 #ifdef HAVE_SYS_FILE_H
diff --git a/gdb/defs.h b/gdb/defs.h
index 710298c..b7271a7 100644
--- a/gdb/defs.h
+++ b/gdb/defs.h
@@ -28,7 +28,6 @@
 #include "common-defs.h"
 
 #include <sys/types.h>
-#include <errno.h>		/* System call error return status.  */
 #include <limits.h>
 #include <stdint.h>
 
diff --git a/gdb/event-loop.c b/gdb/event-loop.c
index cc2f837..e40187e 100644
--- a/gdb/event-loop.c
+++ b/gdb/event-loop.c
@@ -31,7 +31,6 @@
 #endif
 
 #include <sys/types.h>
-#include <errno.h>
 #include <sys/time.h>
 #include "exceptions.h"
 #include "gdb_select.h"
diff --git a/gdb/f-typeprint.c b/gdb/f-typeprint.c
index 534019a..7474051 100644
--- a/gdb/f-typeprint.c
+++ b/gdb/f-typeprint.c
@@ -30,7 +30,6 @@
 #include "gdbcore.h"
 #include "target.h"
 #include "f-lang.h"
-#include <errno.h>
 
 #if 0				/* Currently unused.  */
 static void f_type_print_args (struct type *, struct ui_file *);
diff --git a/gdb/gdbserver/config.in b/gdb/gdbserver/config.in
index 6ce45a6..216c01d 100644
--- a/gdb/gdbserver/config.in
+++ b/gdb/gdbserver/config.in
@@ -54,9 +54,6 @@
 /* Define if <sys/procfs.h> has elf_fpregset_t. */
 #undef HAVE_ELF_FPREGSET_T
 
-/* Define to 1 if you have the <errno.h> header file. */
-#undef HAVE_ERRNO_H
-
 /* Define to 1 if you have the <fcntl.h> header file. */
 #undef HAVE_FCNTL_H
 
diff --git a/gdb/gdbserver/configure b/gdb/gdbserver/configure
index 5f8dcd2..9c1f9a8 100755
--- a/gdb/gdbserver/configure
+++ b/gdb/gdbserver/configure
@@ -4904,7 +4904,7 @@ $as_echo "$as_me: running $SHELL $ac_sub_configure $ac_sub_configure_args --cach
   cd "$ac_popdir"
 
 
-for ac_header in sgtty.h termio.h termios.h sys/reg.h string.h 		 proc_service.h sys/procfs.h linux/elf.h 		 errno.h fcntl.h signal.h sys/file.h malloc.h 		 sys/ioctl.h netinet/in.h sys/socket.h netdb.h 		 netinet/tcp.h arpa/inet.h
+for ac_header in sgtty.h termio.h termios.h sys/reg.h string.h 		 proc_service.h sys/procfs.h linux/elf.h 		 fcntl.h signal.h sys/file.h malloc.h 		 sys/ioctl.h netinet/in.h sys/socket.h netdb.h 		 netinet/tcp.h arpa/inet.h
 do :
   as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
 ac_fn_c_check_header_mongrel "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default"
diff --git a/gdb/gdbserver/configure.ac b/gdb/gdbserver/configure.ac
index 67866f8..8e5d74f 100644
--- a/gdb/gdbserver/configure.ac
+++ b/gdb/gdbserver/configure.ac
@@ -82,7 +82,7 @@ ACX_CONFIGURE_DIR(["../../libiberty"], ["build-libiberty-gdbserver"])
 
 AC_CHECK_HEADERS(sgtty.h termio.h termios.h sys/reg.h string.h dnl
 		 proc_service.h sys/procfs.h linux/elf.h dnl
-		 errno.h fcntl.h signal.h sys/file.h malloc.h dnl
+		 fcntl.h signal.h sys/file.h malloc.h dnl
 		 sys/ioctl.h netinet/in.h sys/socket.h netdb.h dnl
 		 netinet/tcp.h arpa/inet.h)
 AC_CHECK_FUNCS(pread pwrite pread64 readlink)
diff --git a/gdb/gdbserver/event-loop.c b/gdb/gdbserver/event-loop.c
index 1513b59..92c8db0 100644
--- a/gdb/gdbserver/event-loop.c
+++ b/gdb/gdbserver/event-loop.c
@@ -29,10 +29,6 @@
 #include <io.h>
 #endif
 
-#ifdef HAVE_ERRNO_H
-#include <errno.h>
-#endif
-
 #include <unistd.h>
 
 typedef struct gdb_event gdb_event;
diff --git a/gdb/gdbserver/gdbreplay.c b/gdb/gdbserver/gdbreplay.c
index 706fda6..c70abef 100644
--- a/gdb/gdbserver/gdbreplay.c
+++ b/gdb/gdbserver/gdbreplay.c
@@ -32,9 +32,7 @@
 #if HAVE_FCNTL_H
 #include <fcntl.h>
 #endif
-#if HAVE_ERRNO_H
 #include <errno.h>
-#endif
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
diff --git a/gdb/gdbserver/hostio-errno.c b/gdb/gdbserver/hostio-errno.c
index 8817096..f24b51f 100644
--- a/gdb/gdbserver/hostio-errno.c
+++ b/gdb/gdbserver/hostio-errno.c
@@ -22,7 +22,6 @@
    on top of errno.  */
 
 #include "server.h"
-#include <errno.h>
 #include "gdb/fileio.h"
 
 static int
diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c
index 74289c0..f71a4de 100644
--- a/gdb/gdbserver/linux-low.c
+++ b/gdb/gdbserver/linux-low.c
@@ -31,7 +31,6 @@
 #include <sys/ioctl.h>
 #include <fcntl.h>
 #include <unistd.h>
-#include <errno.h>
 #include <sys/syscall.h>
 #include <sched.h>
 #include <ctype.h>
diff --git a/gdb/gdbserver/remote-utils.c b/gdb/gdbserver/remote-utils.c
index f3ae393..327677a 100644
--- a/gdb/gdbserver/remote-utils.c
+++ b/gdb/gdbserver/remote-utils.c
@@ -56,9 +56,6 @@
 #include <arpa/inet.h>
 #endif
 #include <sys/stat.h>
-#if HAVE_ERRNO_H
-#include <errno.h>
-#endif
 
 #if USE_WIN32API
 #include <winsock2.h>
diff --git a/gdb/gdbserver/server.h b/gdb/gdbserver/server.h
index 1e2c3a1..db6ddde 100644
--- a/gdb/gdbserver/server.h
+++ b/gdb/gdbserver/server.h
@@ -27,9 +27,6 @@
 
 #include "version.h"
 
-#ifdef HAVE_ERRNO_H
-#include <errno.h>
-#endif
 #include <setjmp.h>
 
 #ifdef HAVE_ALLOCA_H
diff --git a/gdb/gdbserver/spu-low.c b/gdb/gdbserver/spu-low.c
index cb1ac0d..867f97b 100644
--- a/gdb/gdbserver/spu-low.c
+++ b/gdb/gdbserver/spu-low.c
@@ -24,7 +24,6 @@
 #include <sys/ptrace.h>
 #include <fcntl.h>
 #include <unistd.h>
-#include <errno.h>
 #include <sys/syscall.h>
 #include "filestuff.h"
 #include "hostio.h"
diff --git a/gdb/gdbserver/utils.c b/gdb/gdbserver/utils.c
index ec37a9b..b011637 100644
--- a/gdb/gdbserver/utils.c
+++ b/gdb/gdbserver/utils.c
@@ -17,9 +17,6 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include "server.h"
-#if HAVE_ERRNO_H
-#include <errno.h>
-#endif
 
 #ifdef IN_PROCESS_AGENT
 #  define PREFIX "ipa: "
diff --git a/gdb/gnu-nat.c b/gdb/gnu-nat.c
index d6658c7..c8164d6 100644
--- a/gdb/gnu-nat.c
+++ b/gdb/gnu-nat.c
@@ -23,7 +23,6 @@
 #include "defs.h"
 
 #include <ctype.h>
-#include <errno.h>
 #include <limits.h>
 #include <setjmp.h>
 #include <signal.h>
diff --git a/gdb/go32-nat.c b/gdb/go32-nat.c
index 75596a2..727f810 100644
--- a/gdb/go32-nat.c
+++ b/gdb/go32-nat.c
@@ -105,7 +105,6 @@
 #include "inf-child.h"
 
 #include <ctype.h>
-#include <errno.h>
 #include <unistd.h>
 #include <sys/utsname.h>
 #include <io.h>
diff --git a/gdb/i386gnu-nat.c b/gdb/i386gnu-nat.c
index 94d2a0a..8fad871 100644
--- a/gdb/i386gnu-nat.c
+++ b/gdb/i386gnu-nat.c
@@ -22,7 +22,6 @@
 #include "floatformat.h"
 #include "regcache.h"
 
-#include <errno.h>
 #include <mach.h>
 #include <mach_error.h>
 #include <mach/message.h>
diff --git a/gdb/m2-typeprint.c b/gdb/m2-typeprint.c
index 45bc093..72c107b 100644
--- a/gdb/m2-typeprint.c
+++ b/gdb/m2-typeprint.c
@@ -31,7 +31,6 @@
 #include "c-lang.h"
 #include "typeprint.h"
 #include "cp-abi.h"
-#include <errno.h>
 
 static void m2_print_bounds (struct type *type,
 			     struct ui_file *stream, int show, int level,
diff --git a/gdb/nat/linux-btrace.c b/gdb/nat/linux-btrace.c
index 19e218e..f6fdbda 100644
--- a/gdb/nat/linux-btrace.c
+++ b/gdb/nat/linux-btrace.c
@@ -37,7 +37,6 @@
 
 #if HAVE_LINUX_PERF_EVENT_H && defined(SYS_perf_event_open)
 
-#include <errno.h>
 #include <stdint.h>
 #include <unistd.h>
 #include <sys/mman.h>
diff --git a/gdb/p-typeprint.c b/gdb/p-typeprint.c
index 6870cdf..b1e16f0 100644
--- a/gdb/p-typeprint.c
+++ b/gdb/p-typeprint.c
@@ -31,7 +31,6 @@
 #include "p-lang.h"
 #include "typeprint.h"
 #include "gdb-demangle.h"
-#include <errno.h>
 #include <ctype.h>
 
 static void pascal_type_print_varspec_suffix (struct type *, struct ui_file *,
diff --git a/gdb/procfs.c b/gdb/procfs.c
index d93843a..3465bc5 100644
--- a/gdb/procfs.c
+++ b/gdb/procfs.c
@@ -42,7 +42,6 @@
 #ifdef HAVE_SYS_SYSCALL_H
 #include <sys/syscall.h>
 #endif
-#include <sys/errno.h>
 #include "gdb_wait.h"
 #include <signal.h>
 #include <ctype.h>
diff --git a/gdb/remote-sim.c b/gdb/remote-sim.c
index 51b3c30..8901548 100644
--- a/gdb/remote-sim.c
+++ b/gdb/remote-sim.c
@@ -28,7 +28,6 @@
 #include <fcntl.h>
 #include <signal.h>
 #include <setjmp.h>
-#include <errno.h>
 #include "terminal.h"
 #include "target.h"
 #include "gdbcore.h"
diff --git a/gdb/rs6000-nat.c b/gdb/rs6000-nat.c
index 4ba955c..1b09680 100644
--- a/gdb/rs6000-nat.c
+++ b/gdb/rs6000-nat.c
@@ -46,7 +46,6 @@
 #include <signal.h>
 #include <sys/ioctl.h>
 #include <fcntl.h>
-#include <errno.h>
 
 #include <a.out.h>
 #include <sys/file.h>
diff --git a/gdb/target.c b/gdb/target.c
index b329a13..2c1d35b 100644
--- a/gdb/target.c
+++ b/gdb/target.c
@@ -20,7 +20,6 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include "defs.h"
-#include <errno.h>
 #include "target.h"
 #include "target-dcache.h"
 #include "gdbcmd.h"
diff --git a/gdb/typeprint.c b/gdb/typeprint.c
index e0b7c44..3d8620a 100644
--- a/gdb/typeprint.c
+++ b/gdb/typeprint.c
@@ -33,7 +33,6 @@
 #include "typeprint.h"
 #include "exceptions.h"
 #include "valprint.h"
-#include <errno.h>
 #include <ctype.h>
 #include "cli/cli-utils.h"
 #include "extension.h"
diff --git a/gdb/ui-file.c b/gdb/ui-file.c
index 767b55b..49607dc 100644
--- a/gdb/ui-file.c
+++ b/gdb/ui-file.c
@@ -25,8 +25,6 @@
 #include "gdb_select.h"
 #include "filestuff.h"
 
-#include <errno.h>
-
 static ui_file_isatty_ftype null_file_isatty;
 static ui_file_write_ftype null_file_write;
 static ui_file_write_ftype null_file_write_async_safe;
diff --git a/gdb/valops.c b/gdb/valops.c
index 5ef763d..d9ce2f2 100644
--- a/gdb/valops.c
+++ b/gdb/valops.c
@@ -36,7 +36,6 @@
 #include "cp-support.h"
 #include "dfp.h"
 #include "tracepoint.h"
-#include <errno.h>
 #include "observer.h"
 #include "objfiles.h"
 #include "exceptions.h"
diff --git a/gdb/valprint.c b/gdb/valprint.c
index 0ded6b7..d3ab267 100644
--- a/gdb/valprint.c
+++ b/gdb/valprint.c
@@ -37,8 +37,6 @@
 #include "charset.h"
 #include <ctype.h>
 
-#include <errno.h>
-
 /* Maximum number of wchars returned from wchar_iterate.  */
 #define MAX_WCHARS 4
 
