diff --git a/src/port/preadv.c b/src/port/preadv.c
index 48b64d4593..188e10f065 100644
--- a/src/port/preadv.c
+++ b/src/port/preadv.c
@@ -12,7 +12,7 @@
  */
 
 
-#include "postgres.h"
+#include "c.h"
 
 #include <unistd.h>
 
diff --git a/src/port/pwritev.c b/src/port/pwritev.c
index 8b303fcbcd..de9b7e4e3d 100644
--- a/src/port/pwritev.c
+++ b/src/port/pwritev.c
@@ -12,7 +12,7 @@
  */
 
 
-#include "postgres.h"
+#include "c.h"
 
 #include <unistd.h>
 
diff --git a/src/port/win32pread.c b/src/port/win32pread.c
index 7058c3460b..ebcdd33756 100644
--- a/src/port/win32pread.c
+++ b/src/port/win32pread.c
@@ -12,7 +12,7 @@
  */
 
 
-#include "postgres.h"
+#include "c.h"
 
 #include <windows.h>
 
diff --git a/src/port/win32pwrite.c b/src/port/win32pwrite.c
index 455cec4a74..7f2e62e8a7 100644
--- a/src/port/win32pwrite.c
+++ b/src/port/win32pwrite.c
@@ -12,7 +12,7 @@
  */
 
 
-#include "postgres.h"
+#include "c.h"
 
 #include <windows.h>