diff --git a/src/backend/libpq/auth.c b/src/backend/libpq/auth.c
index 51d167fdfc0..e5f848ec1b4 100644
--- a/src/backend/libpq/auth.c
+++ b/src/backend/libpq/auth.c
@@ -20,6 +20,9 @@
 #include <netinet/in.h>
 #include <arpa/inet.h>
 #include <unistd.h>
+#ifdef HAVE_SYS_SELECT_H
+#include <sys/select.h>
+#endif
 
 #include "libpq/auth.h"
 #include "libpq/crypt.h"
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index ef865174ecb..38f7e70d0a7 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -28,6 +28,9 @@
 #include <arpa/inet.h>
 #include <signal.h>
 #include <time.h>
+#ifdef HAVE_SYS_SELECT_H
+#include <sys/select.h>
+#endif
 
 #include "pgstat.h"
 
diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c
index 1140e766bf0..6b88b734ada 100644
--- a/src/bin/pg_basebackup/pg_basebackup.c
+++ b/src/bin/pg_basebackup/pg_basebackup.c
@@ -27,7 +27,9 @@
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <signal.h>
-
+#ifdef HAVE_SYS_SELECT_H
+#include <sys/select.h>
+#endif
 #ifdef HAVE_LIBZ
 #include <zlib.h>
 #endif
diff --git a/src/bin/pg_basebackup/receivelog.c b/src/bin/pg_basebackup/receivelog.c
index b7f43d5aef0..2e0b52cefb4 100644
--- a/src/bin/pg_basebackup/receivelog.c
+++ b/src/bin/pg_basebackup/receivelog.c
@@ -32,6 +32,9 @@
 #include <sys/time.h>
 #include <sys/types.h>
 #include <unistd.h>
+#ifdef HAVE_SYS_SELECT_H
+#include <sys/select.h>
+#endif
 
 
 /* Size of the streaming replication protocol headers */
diff --git a/src/port/pgsleep.c b/src/port/pgsleep.c
index 0ebeb6528f0..96d467ef8b3 100644
--- a/src/port/pgsleep.c
+++ b/src/port/pgsleep.c
@@ -14,6 +14,9 @@
 
 #include <unistd.h>
 #include <sys/time.h>
+#ifdef HAVE_SYS_SELECT_H
+#include <sys/select.h>
+#endif
 
 /*
  * In a Windows backend, we don't use this implementation, but rather
diff --git a/src/test/examples/testlibpq2.c b/src/test/examples/testlibpq2.c
index 850993f6e82..07c6317a212 100644
--- a/src/test/examples/testlibpq2.c
+++ b/src/test/examples/testlibpq2.c
@@ -34,6 +34,10 @@
 #include <errno.h>
 #include <sys/time.h>
 #include <sys/types.h>
+#ifdef HAVE_SYS_SELECT_H
+#include <sys/select.h>
+#endif
+
 #include "libpq-fe.h"
 
 static void