diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index c3a910d2a7..85d7de25e8 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,11 @@
+2020-01-14  Tom Tromey  <tom@tromey.com>
+
+	* gdbsupport/common.m4 (GDB_AC_COMMON): Define WIN32APILIBS and
+	USE_WIN32API when needed.
+	* configure.ac (USE_WIN32API): Don't define.
+	(WIN32LIBS): Use WIN32APILIBS.
+	* configure: Rebuild.
+
 2020-01-14  Tom Tromey  <tom@tromey.com>
 
 	* configure: Rebuild.
diff --git a/gdb/configure b/gdb/configure
index f9aed98699..fe2d887a1a 100755
--- a/gdb/configure
+++ b/gdb/configure
@@ -688,12 +688,12 @@ TCL_BIN_DIR
 TCL_PATCH_LEVEL
 TCL_VERSION
 WIN32LDAPP
+WIN32LIBS
 GUI_CFLAGS_X
 LIBGUI
 LTLIBLZMA
 LIBLZMA
 HAVE_LIBLZMA
-WIN32LIBS
 SER_HARDWIRE
 WERROR_CFLAGS
 WARN_CFLAGS
@@ -13567,6 +13567,16 @@ _ACEOF
 fi
 
 
+  WIN32APILIBS=
+  case ${host} in
+    *mingw32*)
+
+$as_echo "#define USE_WIN32API 1" >>confdefs.h
+
+      WIN32APILIBS="-lws2_32"
+      ;;
+  esac
+
 
   { $as_echo "$as_me:${as_lineno-$LINENO}: checking for nl_langinfo and CODESET" >&5
 $as_echo_n "checking for nl_langinfo and CODESET... " >&6; }
@@ -16356,15 +16366,8 @@ if test x"$gdb_cv_os_cygwin" = xyes; then
 fi
 
 # The ser-tcp.c module requires sockets.
-case ${host} in
-  *mingw32*)
-
-$as_echo "#define USE_WIN32API 1" >>confdefs.h
-
-    WIN32LIBS="$WIN32LIBS -lws2_32"
-    ;;
-esac
-
+# Note that WIN32APILIBS is set by GDB_AC_COMMON.
+WIN32LIBS="$WIN32LIBS $WIN32APILIBS"
 
 # Add ELF support to GDB, but only if BFD includes ELF support.
 
diff --git a/gdb/configure.ac b/gdb/configure.ac
index ca0da7980c..a7b744bf24 100644
--- a/gdb/configure.ac
+++ b/gdb/configure.ac
@@ -1827,17 +1827,8 @@ if test x"$gdb_cv_os_cygwin" = xyes; then
 fi
 
 # The ser-tcp.c module requires sockets.
-case ${host} in
-  *mingw32*)
-    AC_DEFINE(USE_WIN32API, 1,
-              [Define if we should use the Windows API, instead of the
-	       POSIX API.  On Windows, we use the Windows API when
-	       building for MinGW, but the POSIX API when building
-	       for Cygwin.])
-    WIN32LIBS="$WIN32LIBS -lws2_32"
-    ;;
-esac
-AC_SUBST(WIN32LIBS)
+# Note that WIN32APILIBS is set by GDB_AC_COMMON.
+WIN32LIBS="$WIN32LIBS $WIN32APILIBS"
 
 # Add ELF support to GDB, but only if BFD includes ELF support.
 GDB_AC_CHECK_BFD([for ELF support in BFD], gdb_cv_var_elf,
diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog
index 0010e273ae..6d9e314670 100644
--- a/gdb/gdbserver/ChangeLog
+++ b/gdb/gdbserver/ChangeLog
@@ -1,3 +1,9 @@
+2020-01-14  Tom Tromey  <tom@tromey.com>
+
+	* configure.ac (LIBS): Use WIN32APILIBS.
+	(USE_WIN32API): Don't define.
+	* configure: Rebuild.
+
 2020-01-14  Tom Tromey  <tom@tromey.com>
 
 	* configure: Rebuild.
diff --git a/gdb/gdbserver/configure b/gdb/gdbserver/configure
index 9d262bf58c..154eeac7f0 100755
--- a/gdb/gdbserver/configure
+++ b/gdb/gdbserver/configure
@@ -6959,6 +6959,16 @@ _ACEOF
 fi
 
 
+  WIN32APILIBS=
+  case ${host} in
+    *mingw32*)
+
+$as_echo "#define USE_WIN32API 1" >>confdefs.h
+
+      WIN32APILIBS="-lws2_32"
+      ;;
+  esac
+
 
   { $as_echo "$as_me:${as_lineno-$LINENO}: checking for nl_langinfo and CODESET" >&5
 $as_echo_n "checking for nl_langinfo and CODESET... " >&6; }
@@ -8705,19 +8715,14 @@ esac
 if test "${srv_mingwce}" = "yes"; then
   LIBS="$LIBS -lws2"
 elif test "${srv_mingw}" = "yes"; then
-  LIBS="$LIBS -lws2_32"
+  # WIN32APILIBS is set by GDB_AC_COMMON.
+  LIBS="$LIBS $WIN32APILIBS"
 elif test "${srv_qnx}" = "yes"; then
   LIBS="$LIBS -lsocket"
 elif test "${srv_lynxos}" = "yes"; then
   LIBS="$LIBS -lnetinet"
 fi
 
-if test "${srv_mingw}" = "yes"; then
-
-$as_echo "#define USE_WIN32API 1" >>confdefs.h
-
-fi
-
 if test "${srv_linux_usrregs}" = "yes"; then
 
 $as_echo "#define HAVE_LINUX_USRREGS 1" >>confdefs.h
diff --git a/gdb/gdbserver/configure.ac b/gdb/gdbserver/configure.ac
index 817a861a32..fab765ea38 100644
--- a/gdb/gdbserver/configure.ac
+++ b/gdb/gdbserver/configure.ac
@@ -248,21 +248,14 @@ esac
 if test "${srv_mingwce}" = "yes"; then
   LIBS="$LIBS -lws2"
 elif test "${srv_mingw}" = "yes"; then
-  LIBS="$LIBS -lws2_32"
+  # WIN32APILIBS is set by GDB_AC_COMMON.
+  LIBS="$LIBS $WIN32APILIBS"
 elif test "${srv_qnx}" = "yes"; then
   LIBS="$LIBS -lsocket"
 elif test "${srv_lynxos}" = "yes"; then
   LIBS="$LIBS -lnetinet"
 fi
 
-if test "${srv_mingw}" = "yes"; then
-  AC_DEFINE(USE_WIN32API, 1,
-	    [Define if we should use the Windows API, instead of the
-	     POSIX API.  On Windows, we use the Windows API when
-	     building for MinGW, but the POSIX API when building
-	     for Cygwin.])
-fi
-
 if test "${srv_linux_usrregs}" = "yes"; then
   AC_DEFINE(HAVE_LINUX_USRREGS, 1,
 	    [Define if the target supports PTRACE_PEEKUSR for register ]
diff --git a/gdb/gdbsupport/common.m4 b/gdb/gdbsupport/common.m4
index f070de379e..9e15940eea 100644
--- a/gdb/gdbsupport/common.m4
+++ b/gdb/gdbsupport/common.m4
@@ -21,6 +21,18 @@ AC_DEFUN([GDB_AC_COMMON], [
   AC_HEADER_STDC
   AC_FUNC_ALLOCA
 
+  WIN32APILIBS=
+  case ${host} in
+    *mingw32*)
+      AC_DEFINE(USE_WIN32API, 1,
+		[Define if we should use the Windows API, instead of the
+		 POSIX API.  On Windows, we use the Windows API when
+		 building for MinGW, but the POSIX API when building
+		 for Cygwin.])
+      WIN32APILIBS="-lws2_32"
+      ;;
+  esac
+
   dnl Note that this requires codeset.m4, which is included
   dnl by the users of common.m4.
   AM_LANGINFO_CODESET