diff --git a/source/i18n/L10n.cpp b/source/i18n/L10n.cpp
index 890ca30f57..0eb643984e 100644
--- a/source/i18n/L10n.cpp
+++ b/source/i18n/L10n.cpp
@@ -26,7 +26,7 @@
 
 #include <boost/algorithm/string.hpp>
 #include <boost/concept_check.hpp>
-#include <iostream>
+#include <sstream>
 #include <string>
 
 #include "gui/GUIManager.h"
diff --git a/source/main.cpp b/source/main.cpp
index b7e8e83eb0..8889d5a202 100644
--- a/source/main.cpp
+++ b/source/main.cpp
@@ -81,6 +81,7 @@ that of Atlas depending on commandline parameters.
 #include "soundmanager/ISoundManager.h"
 
 #if OS_UNIX
+#include <iostream>
 #include <unistd.h> // geteuid
 #endif // OS_UNIX
 
@@ -94,7 +95,6 @@ that of Atlas depending on commandline parameters.
 #endif
 
 #include <chrono>
-#include <iostream>
 
 extern CmdLineArgs g_args;
 extern CStrW g_UniqueLogPostfix;
diff --git a/source/ps/CLogger.cpp b/source/ps/CLogger.cpp
index 8ce3b45dad..f7e6129c99 100644
--- a/source/ps/CLogger.cpp
+++ b/source/ps/CLogger.cpp
@@ -1,4 +1,4 @@
-/* Copyright (C) 2019 Wildfire Games.
+/* Copyright (C) 2021 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -22,7 +22,6 @@
 #include "graphics/FontMetrics.h"
 #include "graphics/ShaderManager.h"
 #include "graphics/TextRenderer.h"
-#include "lib/ogl.h"
 #include "lib/timer.h"
 #include "lib/utf8.h"
 #include "ps/CConsole.h"
@@ -31,6 +30,7 @@
 #include "renderer/Renderer.h"
 
 #include <ctime>
+#include <fstream>
 #include <iostream>
 
 #include <boost/algorithm/string/replace.hpp>
diff --git a/source/ps/CLogger.h b/source/ps/CLogger.h
index a41f984f8b..20d881619e 100644
--- a/source/ps/CLogger.h
+++ b/source/ps/CLogger.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2019 Wildfire Games.
+/* Copyright (C) 2021 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -19,10 +19,8 @@
 #define INCLUDED_CLOGGER
 
 #include <deque>
-#include <fstream>
 #include <mutex>
 #include <string>
-#include <set>
 #include <sstream>
 
 #include <fmt/printf.h>
diff --git a/source/ps/ModInstaller.cpp b/source/ps/ModInstaller.cpp
index 25161f0af1..4cb4c5fd74 100644
--- a/source/ps/ModInstaller.cpp
+++ b/source/ps/ModInstaller.cpp
@@ -23,7 +23,9 @@
 #include "ps/Filesystem.h"
 #include "ps/XML/Xeromyces.h"
 
+#ifdef OS_WIN
 #include <fstream>
+#endif
 
 CModInstaller::CModInstaller(const OsPath& modsdir, const OsPath& tempdir) :
 	m_ModsDir(modsdir), m_TempDir(tempdir / "_modscache"), m_CacheDir("cache/")
diff --git a/source/scriptinterface/ScriptInterface.cpp b/source/scriptinterface/ScriptInterface.cpp
index 6e6248d018..b01ee350bb 100644
--- a/source/scriptinterface/ScriptInterface.cpp
+++ b/source/scriptinterface/ScriptInterface.cpp
@@ -30,8 +30,8 @@
 #include "ps/Profile.h"
 #include "ps/utf16string.h"
 
-#include <cassert>
 #include <map>
+#include <string>
 
 #define BOOST_MULTI_INDEX_DISABLE_SERIALIZATION
 #include <boost/preprocessor/punctuation/comma_if.hpp>
diff --git a/source/simulation2/serialization/BinarySerializer.h b/source/simulation2/serialization/BinarySerializer.h
index 9dbbae4080..cdd9ac4a03 100644
--- a/source/simulation2/serialization/BinarySerializer.h
+++ b/source/simulation2/serialization/BinarySerializer.h
@@ -25,8 +25,7 @@
 #include "js/AllocPolicy.h"
 #include "js/GCHashTable.h"
 
-#include <iostream>
-#include <map>
+#include <ostream>
 #include <streambuf>
 
 /**
diff --git a/source/tools/atlas/AtlasObject/AtlasObjectXML.cpp b/source/tools/atlas/AtlasObject/AtlasObjectXML.cpp
index 0c5cf2613c..495e315e56 100644
--- a/source/tools/atlas/AtlasObject/AtlasObjectXML.cpp
+++ b/source/tools/atlas/AtlasObject/AtlasObjectXML.cpp
@@ -1,4 +1,4 @@
-/* Copyright (C) 2019 Wildfire Games.
+/* Copyright (C) 2021 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -19,12 +19,8 @@
 #include "AtlasObjectImpl.h"
 
 #include <cassert>
-#include <cstring>
-
-#include <memory>
-#include <fstream>
-
 #include <libxml/parser.h>
+#include <string>
 
 // TODO: replace most of the asserts below (e.g. for when it fails to load
 // a file) with some proper logging/reporting system