diff --git a/examples/pdf-mod-info.cc b/examples/pdf-mod-info.cc
index 06fcf17..03fa235 100644
--- a/examples/pdf-mod-info.cc
+++ b/examples/pdf-mod-info.cc
@@ -9,13 +9,6 @@
 #include <string.h>
 #include <stdlib.h>
 #include <stdio.h>
-#ifdef _WIN32
-#include <windows.h>
-#include <direct.h>
-#include <io.h>
-#else
-#include <unistd.h>
-#endif
 
 static char const* version = "1.1";
 static char const* whoami = 0;
diff --git a/libqpdf/QUtil.cc b/libqpdf/QUtil.cc
index 4df76fa..c5dfa74 100644
--- a/libqpdf/QUtil.cc
+++ b/libqpdf/QUtil.cc
@@ -28,6 +28,7 @@
 # include <cwchar>
 #endif
 #ifdef _WIN32
+# define WIN32_LEAN_AND_MEAN
 # include <windows.h>
 # include <direct.h>
 # include <io.h>
diff --git a/libqpdf/SecureRandomDataProvider.cc b/libqpdf/SecureRandomDataProvider.cc
index 87839dc..705046c 100644
--- a/libqpdf/SecureRandomDataProvider.cc
+++ b/libqpdf/SecureRandomDataProvider.cc
@@ -3,6 +3,7 @@
 #include <qpdf/qpdf-config.h>
 #include <qpdf/QUtil.hh>
 #ifdef _WIN32
+# define WIN32_LEAN_AND_MEAN
 # include <windows.h>
 # include <direct.h>
 # include <io.h>
diff --git a/qpdf/test_unicode_filenames.cc b/qpdf/test_unicode_filenames.cc
index 45701a9..3ef71be 100644
--- a/qpdf/test_unicode_filenames.cc
+++ b/qpdf/test_unicode_filenames.cc
@@ -1,7 +1,8 @@
 #ifdef _WIN32
-#include <windows.h>
-#include <direct.h>
-#include <io.h>
+# define WIN32_LEAN_AND_MEAN
+# include <windows.h>
+# include <direct.h>
+# include <io.h>
 #endif
 
 #include <iostream>