diff --git a/configure b/configure
index acec60c3a7..9049ad015e 100755
--- a/configure
+++ b/configure
@@ -19254,8 +19254,7 @@ fi
 
 
 
-
-for ac_func in cbrt dlopen fdatasync getifaddrs getpeerucred getrlimit memmove poll pstat readlink setproctitle setsid sigprocmask symlink towlower utime utimes waitpid wcstombs wcstombs_l
+for ac_func in cbrt dlopen fdatasync getifaddrs getpeerucred getrlimit memmove poll pstat readlink setproctitle setsid sigprocmask symlink towlower utime utimes wcstombs wcstombs_l
 do
 as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
 { $as_echo "$as_me:$LINENO: checking for $ac_func" >&5
diff --git a/configure.in b/configure.in
index 05e6324e8f..a362cfdf5e 100644
--- a/configure.in
+++ b/configure.in
@@ -1207,7 +1207,7 @@ PGAC_VAR_INT_TIMEZONE
 AC_FUNC_ACCEPT_ARGTYPES
 PGAC_FUNC_GETTIMEOFDAY_1ARG
 
-AC_CHECK_FUNCS([cbrt dlopen fdatasync getifaddrs getpeerucred getrlimit memmove poll pstat readlink setproctitle setsid sigprocmask symlink towlower utime utimes waitpid wcstombs wcstombs_l])
+AC_CHECK_FUNCS([cbrt dlopen fdatasync getifaddrs getpeerucred getrlimit memmove poll pstat readlink setproctitle setsid sigprocmask symlink towlower utime utimes wcstombs wcstombs_l])
 
 AC_REPLACE_FUNCS(fseeko)
 case $host_os in
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index 913734fbd0..45f6ac624e 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -377,7 +377,9 @@ static void InitPostmasterDeathWatchHandle(void);
 #ifdef EXEC_BACKEND
 
 #ifdef WIN32
-static pid_t win32_waitpid(int *exitstatus);
+#define WNOHANG 0				/* ignored, so any integer value will do */
+
+static pid_t waitpid(pid_t pid, int *exitstatus, int options);
 static void WINAPI pgwin32_deadchild_callback(PVOID lpParameter, BOOLEAN TimerOrWaitFired);
 
 static HANDLE win32ChildQueue;
@@ -388,7 +390,7 @@ typedef struct
 	HANDLE		procHandle;
 	DWORD		procId;
 } win32_deadchild_waitinfo;
-#endif
+#endif /* WIN32 */
 
 static pid_t backend_forkexec(Port *port);
 static pid_t internal_forkexec(int argc, char *argv[], Port *port);
@@ -2268,33 +2270,13 @@ reaper(SIGNAL_ARGS)
 	int			pid;			/* process id of dead child process */
 	int			exitstatus;		/* its exit status */
 
-	/* These macros hide platform variations in getting child status */
-#ifdef HAVE_WAITPID
-	int			status;			/* child exit status */
-
-#define LOOPTEST()		((pid = waitpid(-1, &status, WNOHANG)) > 0)
-#define LOOPHEADER()	(exitstatus = status)
-#else							/* !HAVE_WAITPID */
-#ifndef WIN32
-	union wait	status;			/* child exit status */
-
-#define LOOPTEST()		((pid = wait3(&status, WNOHANG, NULL)) > 0)
-#define LOOPHEADER()	(exitstatus = status.w_status)
-#else							/* WIN32 */
-#define LOOPTEST()		((pid = win32_waitpid(&exitstatus)) > 0)
-#define LOOPHEADER()
-#endif   /* WIN32 */
-#endif   /* HAVE_WAITPID */
-
 	PG_SETMASK(&BlockSig);
 
 	ereport(DEBUG4,
 			(errmsg_internal("reaping dead processes")));
 
-	while (LOOPTEST())
+	while ((pid = waitpid(-1, &exitstatus, WNOHANG)) > 0)
 	{
-		LOOPHEADER();
-
 		/*
 		 * Check if this child was a startup process.
 		 */
@@ -5045,8 +5027,12 @@ ShmemBackendArrayRemove(Backend *bn)
 
 #ifdef WIN32
 
+/*
+ * Subset implementation of waitpid() for Windows.  We assume pid is -1
+ * (that is, check all child processes) and options is WNOHANG (don't wait).
+ */
 static pid_t
-win32_waitpid(int *exitstatus)
+waitpid(pid_t pid, int *exitstatus, int options)
 {
 	DWORD		dwd;
 	ULONG_PTR	key;
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 5454efdcbe..6521c6d5b9 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -614,9 +614,6 @@
 /* Define to 1 if you have the `vsnprintf' function. */
 #undef HAVE_VSNPRINTF
 
-/* Define to 1 if you have the `waitpid' function. */
-#undef HAVE_WAITPID
-
 /* Define to 1 if you have the <wchar.h> header file. */
 #undef HAVE_WCHAR_H
 
diff --git a/src/include/pg_config.h.win32 b/src/include/pg_config.h.win32
index 9574a8bbc7..8c232f67a0 100644
--- a/src/include/pg_config.h.win32
+++ b/src/include/pg_config.h.win32
@@ -505,9 +505,6 @@
 /* Define to 1 if you have the `vsnprintf' function. */
 #define HAVE_VSNPRINTF 1
 
-/* Define to 1 if you have the `waitpid' function. */
-/* #undef HAVE_WAITPID */
-
 /* Define to 1 if you have the <wchar.h> header file. */
 #define HAVE_WCHAR_H 1