diff --git a/app/errors.c b/app/errors.c
index d12be158c3..c04a83f887 100644
--- a/app/errors.c
+++ b/app/errors.c
@@ -32,6 +32,9 @@
 #include <gegl.h>
 
 #include "libgimpbase/gimpbase.h"
+#ifdef G_OS_WIN32
+#include "libgimpbase/gimpwin32-io.h"
+#endif
 
 #include "core/core-types.h"
 
diff --git a/app/tests/test-xcf.c b/app/tests/test-xcf.c
index 6ee8c1c466..877d0b51b8 100644
--- a/app/tests/test-xcf.c
+++ b/app/tests/test-xcf.c
@@ -23,7 +23,7 @@
 #include <unistd.h>
 #endif
 
-#ifdef G_OS_WIN32
+#ifdef _WIN32
 #define STRICT
 #define WIN32_LEAN_AND_MEAN
 #include <windows.h>
diff --git a/app/text/gimpfontfactory.c b/app/text/gimpfontfactory.c
index b3baee7ed1..0d2ce9133f 100644
--- a/app/text/gimpfontfactory.c
+++ b/app/text/gimpfontfactory.c
@@ -23,6 +23,10 @@
 
 #include "config.h"
 
+#ifdef _WIN32
+#include <io.h>
+#endif
+
 #include <fcntl.h>
 #include <glib/gstdio.h>
 #include <gdk-pixbuf/gdk-pixbuf.h>
diff --git a/app/tools/gimptool.c b/app/tools/gimptool.c
index 727c851391..3ef0836c1e 100644
--- a/app/tools/gimptool.c
+++ b/app/tools/gimptool.c
@@ -17,6 +17,10 @@
 
 #include "config.h"
 
+#ifdef _WIN32
+#include <stdio.h>
+#endif
+
 #include <gegl.h>
 #include <gtk/gtk.h>
 
diff --git a/libgimpbase/gimpenv.c b/libgimpbase/gimpenv.c
index 13a2a9dabf..420dbd3e37 100644
--- a/libgimpbase/gimpenv.c
+++ b/libgimpbase/gimpenv.c
@@ -36,6 +36,10 @@
 #include <gio/gio.h>
 #include <glib/gstdio.h>
 
+#ifdef G_OS_WIN32
+#include "libgimpbase/gimpwin32-io.h"
+#endif
+
 #include "gimpbasetypes.h"
 
 #define __GIMP_ENV_C__
diff --git a/plug-ins/common/file-compressor.c b/plug-ins/common/file-compressor.c
index f82b30504d..28c83c3149 100644
--- a/plug-ins/common/file-compressor.c
+++ b/plug-ins/common/file-compressor.c
@@ -78,6 +78,9 @@
 #ifdef HAVE_UNISTD_H
 #include <unistd.h>
 #endif
+#ifdef _WIN32
+#include <io.h>
+#endif
 
 #include <glib/gstdio.h>
 #ifndef _O_BINARY
diff --git a/tools/gimp-test-clipboard.c b/tools/gimp-test-clipboard.c
index 7ebf3565a2..974d3b70fa 100644
--- a/tools/gimp-test-clipboard.c
+++ b/tools/gimp-test-clipboard.c
@@ -17,6 +17,11 @@
 #ifdef HAVE_UNISTD_H
 #include <unistd.h>
 #endif
+#if defined(_WIN32) && !defined(HAVE_UNISTD_H)
+#include <io.h>
+#define popen  _popen
+#define pclose _pclose
+#endif
 
 #include <glib/gstdio.h>
 #ifndef _O_BINARY
diff --git a/tools/gimptool.c b/tools/gimptool.c
index c83f416996..2b03ac0e2d 100644
--- a/tools/gimptool.c
+++ b/tools/gimptool.c
@@ -37,6 +37,11 @@
 
 #ifdef G_OS_WIN32
 #include "libgimpbase/gimpwin32-io.h"
+#ifndef HAVE_UNISTD_H
+#include <io.h>
+#define popen  _popen
+#define pclose _pclose
+#endif
 #endif