diff --git a/.github/workflows/iwyu.yml b/.github/workflows/iwyu.yml
index 080c8a8e4..667c0ee3f 100644
--- a/.github/workflows/iwyu.yml
+++ b/.github/workflows/iwyu.yml
@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-22.04
 
     container:
-      image: "kalilinux/kali-rolling"
+      image: "debian:unstable" # use latest debian image to get latest include-what-you-get
 
     steps:
       - uses: actions/checkout@v2
diff --git a/cli/cmdlineparser.cpp b/cli/cmdlineparser.cpp
index b16af080c..a18c29bce 100644
--- a/cli/cmdlineparser.cpp
+++ b/cli/cmdlineparser.cpp
@@ -40,7 +40,7 @@
 #include <iostream>
 #include <list>
 #include <set>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <utility>
 
 #ifdef HAVE_RULES
diff --git a/cli/cppcheckexecutor.cpp b/cli/cppcheckexecutor.cpp
index 0630eb29f..570571f14 100644
--- a/cli/cppcheckexecutor.cpp
+++ b/cli/cppcheckexecutor.cpp
@@ -48,7 +48,7 @@
 #include <iostream>
 #include <list>
 #include <memory>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <utility>
 #include <vector>
 
diff --git a/cli/cppcheckexecutorseh.h b/cli/cppcheckexecutorseh.h
index 487cc9221..5f6d41aeb 100644
--- a/cli/cppcheckexecutorseh.h
+++ b/cli/cppcheckexecutorseh.h
@@ -19,7 +19,7 @@
 #ifndef CPPCHECKEXECUTORSEH_H
 #define CPPCHECKEXECUTORSEH_H
 
-#include "config.h"
+#include "config.h" // IWYU pragma: keep
 
 #ifdef USE_WINDOWS_SEH
 
diff --git a/cli/processexecutor.cpp b/cli/processexecutor.cpp
index ed11ee731..10d7a2146 100644
--- a/cli/processexecutor.cpp
+++ b/cli/processexecutor.cpp
@@ -39,7 +39,7 @@
 #include <functional>
 #include <iostream>
 #include <list>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <sys/select.h>
 #include <sys/wait.h>
 #include <unistd.h>
diff --git a/gui/application.cpp b/gui/application.cpp
index 84ce0fdf9..af68f98bb 100644
--- a/gui/application.cpp
+++ b/gui/application.cpp
@@ -18,6 +18,8 @@
 
 #include "application.h"
 
+#include <utility>
+
 Application::Application(QString name, QString path,
                          QString params)
     : mName(std::move(name))
diff --git a/gui/cppchecklibrarydata.cpp b/gui/cppchecklibrarydata.cpp
index 7c6bf8636..37b0179ed 100644
--- a/gui/cppchecklibrarydata.cpp
+++ b/gui/cppchecklibrarydata.cpp
@@ -19,6 +19,7 @@
 #include "cppchecklibrarydata.h"
 
 #include <stdexcept>
+#include <string>
 
 #include <QXmlStreamReader>
 #include <QVariant>
diff --git a/gui/erroritem.h b/gui/erroritem.h
index cd550dfcd..7bebde0dc 100644
--- a/gui/erroritem.h
+++ b/gui/erroritem.h
@@ -20,6 +20,7 @@
 #define ERRORITEM_H
 
 #include "errorlogger.h"
+#include "errortypes.h"
 
 #include <QList>
 #include <QMetaType>
diff --git a/gui/projectfile.h b/gui/projectfile.h
index 0e60ddbb9..fea4546ff 100644
--- a/gui/projectfile.h
+++ b/gui/projectfile.h
@@ -24,6 +24,7 @@
 
 #include <cstddef>
 #include <map>
+#include <utility>
 
 #include <QObject>
 #include <QString>
diff --git a/gui/report.cpp b/gui/report.cpp
index 45890ab43..f6d757b9d 100644
--- a/gui/report.cpp
+++ b/gui/report.cpp
@@ -18,6 +18,8 @@
 
 #include "report.h"
 
+#include <utility>
+
 Report::Report(QString filename) :
     QObject(),
     mFilename(std::move(filename))
diff --git a/gui/resultstree.cpp b/gui/resultstree.cpp
index 7eada6f4c..5ca7862ea 100644
--- a/gui/resultstree.cpp
+++ b/gui/resultstree.cpp
@@ -21,6 +21,7 @@
 #include "application.h"
 #include "applicationlist.h"
 #include "common.h"
+#include "config.h"
 #include "erroritem.h"
 #include "path.h"
 #include "projectfile.h"
diff --git a/lib/astutils.cpp b/lib/astutils.cpp
index baf6e1c15..8b8bf9085 100644
--- a/lib/astutils.cpp
+++ b/lib/astutils.cpp
@@ -34,6 +34,7 @@
 #include "checkclass.h"
 
 #include <algorithm>
+#include <cassert>
 #include <functional>
 #include <initializer_list>
 #include <iterator>
diff --git a/lib/check.cpp b/lib/check.cpp
index af899c4f8..3a648b28d 100644
--- a/lib/check.cpp
+++ b/lib/check.cpp
@@ -28,6 +28,7 @@
 
 #include <cctype>
 #include <iostream>
+#include <utility>
 
 //---------------------------------------------------------------------------
 
diff --git a/lib/checkcondition.cpp b/lib/checkcondition.cpp
index f9da0661d..7637689c8 100644
--- a/lib/checkcondition.cpp
+++ b/lib/checkcondition.cpp
@@ -37,7 +37,6 @@
 #include <limits>
 #include <list>
 #include <memory>
-#include <ostream>
 #include <set>
 #include <sstream>
 #include <utility>
diff --git a/lib/checkfunctions.cpp b/lib/checkfunctions.cpp
index aad634181..bd18f6b98 100644
--- a/lib/checkfunctions.cpp
+++ b/lib/checkfunctions.cpp
@@ -31,7 +31,6 @@
 #include "valueflow.h"
 
 #include <iomanip>
-#include <ostream>
 #include <sstream>
 #include <unordered_map>
 #include <vector>
diff --git a/lib/checkio.cpp b/lib/checkio.cpp
index 8541ef549..0623c714f 100644
--- a/lib/checkio.cpp
+++ b/lib/checkio.cpp
@@ -35,7 +35,7 @@
 #include <map>
 #include <memory>
 #include <set>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <unordered_set>
 #include <utility>
 #include <vector>
diff --git a/lib/checkother.cpp b/lib/checkother.cpp
index b351ad406..2eb06413b 100644
--- a/lib/checkother.cpp
+++ b/lib/checkother.cpp
@@ -39,7 +39,6 @@
 #include <list>
 #include <map>
 #include <memory>
-#include <ostream>
 #include <set>
 #include <sstream>
 #include <utility>
diff --git a/lib/checktype.cpp b/lib/checktype.cpp
index 0254a7cc2..a016a0080 100644
--- a/lib/checktype.cpp
+++ b/lib/checktype.cpp
@@ -31,7 +31,6 @@
 
 #include <cmath>
 #include <list>
-#include <ostream>
 #include <sstream>
 #include <vector>
 
diff --git a/lib/checkunusedfunctions.cpp b/lib/checkunusedfunctions.cpp
index ce201750c..444086031 100644
--- a/lib/checkunusedfunctions.cpp
+++ b/lib/checkunusedfunctions.cpp
@@ -34,9 +34,8 @@
 #include <cctype>
 #include <cstdlib>
 #include <cstring>
-#include <istream>
 #include <memory>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <utility>
 #include <vector>
 
diff --git a/lib/checkvaarg.cpp b/lib/checkvaarg.cpp
index 2a2381488..8dfbea4a1 100644
--- a/lib/checkvaarg.cpp
+++ b/lib/checkvaarg.cpp
@@ -26,7 +26,6 @@
 #include "tokenize.h"
 
 #include <cstddef>
-#include <list>
 #include <vector>
 
 //---------------------------------------------------------------------------
diff --git a/lib/clangimport.cpp b/lib/clangimport.cpp
index 7ece09c63..671cb2e44 100644
--- a/lib/clangimport.cpp
+++ b/lib/clangimport.cpp
@@ -37,7 +37,7 @@
 #include <map>
 #include <memory>
 #include <set>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <stack>
 #include <string>
 #include <utility>
diff --git a/lib/cppcheck.cpp b/lib/cppcheck.cpp
index 9aafd11e5..ac900dd7b 100644
--- a/lib/cppcheck.cpp
+++ b/lib/cppcheck.cpp
@@ -49,7 +49,7 @@
 #include <memory>
 #include <new>
 #include <set>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <stdexcept>
 #include <string>
 #include <utility>
diff --git a/lib/ctu.cpp b/lib/ctu.cpp
index d569d51f7..ad04bbd52 100644
--- a/lib/ctu.cpp
+++ b/lib/ctu.cpp
@@ -33,7 +33,6 @@
 #include <cstdint>
 #include <cstring>
 #include <iterator>  // back_inserter
-#include <ostream>
 #include <sstream>
 #include <utility>
 
diff --git a/lib/errorlogger.cpp b/lib/errorlogger.cpp
index e6124ed9f..3b4150a5c 100644
--- a/lib/errorlogger.cpp
+++ b/lib/errorlogger.cpp
@@ -33,7 +33,7 @@
 #include <cstring>
 #include <iomanip>
 #include <memory>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <string>
 #include <utility>
 
diff --git a/lib/importproject.cpp b/lib/importproject.cpp
index 76ebb0aa6..cc0da48b7 100644
--- a/lib/importproject.cpp
+++ b/lib/importproject.cpp
@@ -32,7 +32,7 @@
 #include <fstream> // IWYU pragma: keep
 #include <iostream>
 #include <iterator>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <utility>
 
 #include <tinyxml2.h>
diff --git a/lib/library.cpp b/lib/library.cpp
index 16e0655b2..ed902c9fe 100644
--- a/lib/library.cpp
+++ b/lib/library.cpp
@@ -31,10 +31,9 @@
 #include <climits>
 #include <cstdlib>
 #include <cstring>
-#include <iosfwd>
 #include <list>
 #include <memory>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <stack>
 #include <string>
 
diff --git a/lib/path.cpp b/lib/path.cpp
index 5a382a28f..69674ad34 100644
--- a/lib/path.cpp
+++ b/lib/path.cpp
@@ -19,12 +19,14 @@
 #if defined(__GNUC__) && (defined(_WIN32) || defined(__CYGWIN__))
 #undef __STRICT_ANSI__
 #endif
+
 #include "path.h"
 #include "utils.h"
 
 #include <algorithm>
 #include <cstdlib>
 #include <fstream>
+#include <utility>
 
 #ifndef _WIN32
 #include <unistd.h>
diff --git a/lib/preprocessor.cpp b/lib/preprocessor.cpp
index adc704fde..860402ef1 100644
--- a/lib/preprocessor.cpp
+++ b/lib/preprocessor.cpp
@@ -31,7 +31,7 @@
 #include <cstddef>
 #include <iterator> // back_inserter
 #include <memory>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <utility>
 
 #include <simplecpp.h>
diff --git a/lib/summaries.cpp b/lib/summaries.cpp
index 3f847c94f..d0c561977 100644
--- a/lib/summaries.cpp
+++ b/lib/summaries.cpp
@@ -26,9 +26,10 @@
 #include "tokenlist.h"
 
 #include <algorithm>
-#include <fstream>
+#include <fstream> // IWYU pragma: keep
 #include <map>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
+#include <utility>
 #include <vector>
 
 
diff --git a/lib/suppressions.cpp b/lib/suppressions.cpp
index e721807f3..b1cde0c4f 100644
--- a/lib/suppressions.cpp
+++ b/lib/suppressions.cpp
@@ -31,7 +31,8 @@
 #include <cstdlib>
 #include <cstring>
 #include <functional> // std::bind, std::placeholders
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
+#include <utility>
 
 #include <tinyxml2.h>
 
diff --git a/lib/symboldatabase.cpp b/lib/symboldatabase.cpp
index 75029ccf6..55feedf1a 100644
--- a/lib/symboldatabase.cpp
+++ b/lib/symboldatabase.cpp
@@ -41,7 +41,7 @@
 #include <iomanip>
 #include <iostream>
 #include <limits>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <stack>
 #include <string>
 #include <type_traits>
diff --git a/lib/templatesimplifier.cpp b/lib/templatesimplifier.cpp
index 3b12a742b..f10b3bc69 100644
--- a/lib/templatesimplifier.cpp
+++ b/lib/templatesimplifier.cpp
@@ -32,7 +32,7 @@
 #include <iostream>
 #include <map>
 #include <memory>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <stack>
 #include <utility>
 
diff --git a/lib/token.cpp b/lib/token.cpp
index c0362a35e..50bd41945 100644
--- a/lib/token.cpp
+++ b/lib/token.cpp
@@ -40,7 +40,7 @@
 #include <iterator>
 #include <map>
 #include <set>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <stack>
 #include <unordered_set>
 #include <utility>
diff --git a/lib/tokenize.cpp b/lib/tokenize.cpp
index 992e2f51d..ab6219551 100644
--- a/lib/tokenize.cpp
+++ b/lib/tokenize.cpp
@@ -44,7 +44,7 @@
 #include <exception>
 #include <memory>
 #include <set>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <stack>
 #include <stdexcept>
 #include <type_traits>
diff --git a/lib/tokenlist.cpp b/lib/tokenlist.cpp
index 1d90e230c..33f867d7d 100644
--- a/lib/tokenlist.cpp
+++ b/lib/tokenlist.cpp
@@ -31,7 +31,6 @@
 
 #include <algorithm>
 #include <cctype>
-#include <cstring>
 #include <exception>
 #include <functional>
 #include <utility>
diff --git a/lib/valueflow.cpp b/lib/valueflow.cpp
index 73e295c9a..a02fde18d 100644
--- a/lib/valueflow.cpp
+++ b/lib/valueflow.cpp
@@ -105,7 +105,6 @@
 #include <array>
 #include <cassert>
 #include <climits>
-#include <cmath>
 #include <cstdlib>
 #include <cstring>
 #include <exception>
diff --git a/test/test64bit.cpp b/test/test64bit.cpp
index fbe40c57a..c6d560259 100644
--- a/test/test64bit.cpp
+++ b/test/test64bit.cpp
@@ -23,8 +23,7 @@
 #include "testsuite.h"
 #include "tokenize.h"
 
-#include <iosfwd>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 
 class Test64BitPortability : public TestFixture {
 public:
diff --git a/test/testassert.cpp b/test/testassert.cpp
index 699d773ae..07fa34d05 100644
--- a/test/testassert.cpp
+++ b/test/testassert.cpp
@@ -23,8 +23,7 @@
 #include "testsuite.h"
 #include "tokenize.h"
 
-#include <iosfwd>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 
 
 class TestAssert : public TestFixture {
diff --git a/test/testastutils.cpp b/test/testastutils.cpp
index 029eff8e0..a47ca1d10 100644
--- a/test/testastutils.cpp
+++ b/test/testastutils.cpp
@@ -26,8 +26,7 @@
 #include "tokenlist.h"
 
 #include <cstring>
-#include <iosfwd>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 
 class TestAstUtils : public TestFixture {
 public:
diff --git a/test/testautovariables.cpp b/test/testautovariables.cpp
index 367a12f32..9a97dafb8 100644
--- a/test/testautovariables.cpp
+++ b/test/testautovariables.cpp
@@ -23,8 +23,7 @@
 #include "testsuite.h"
 #include "tokenize.h"
 
-#include <iosfwd>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 
 class TestAutoVariables : public TestFixture {
 public:
diff --git a/test/testbool.cpp b/test/testbool.cpp
index 9e2c880e4..f278bce2d 100644
--- a/test/testbool.cpp
+++ b/test/testbool.cpp
@@ -23,8 +23,7 @@
 #include "testsuite.h"
 #include "tokenize.h"
 
-#include <iosfwd>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 
 class TestBool : public TestFixture {
 public:
diff --git a/test/testboost.cpp b/test/testboost.cpp
index 5e0d9952a..4b95a2ea8 100644
--- a/test/testboost.cpp
+++ b/test/testboost.cpp
@@ -23,8 +23,7 @@
 #include "testsuite.h"
 #include "tokenize.h"
 
-#include <iosfwd>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 
 class TestBoost : public TestFixture {
 public:
diff --git a/test/testbufferoverrun.cpp b/test/testbufferoverrun.cpp
index aafeb3eaa..e3d84320e 100644
--- a/test/testbufferoverrun.cpp
+++ b/test/testbufferoverrun.cpp
@@ -28,10 +28,9 @@
 #include "testsuite.h"
 #include "tokenize.h"
 
-#include <iosfwd>
 #include <map>
 #include <list>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <string>
 #include <utility>
 #include <vector>
diff --git a/test/testcharvar.cpp b/test/testcharvar.cpp
index 2b0f09fd3..ff60e93c5 100644
--- a/test/testcharvar.cpp
+++ b/test/testcharvar.cpp
@@ -24,8 +24,7 @@
 #include "testsuite.h"
 #include "tokenize.h"
 
-#include <iosfwd>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 
 class TestCharVar : public TestFixture {
 public:
diff --git a/test/testclangimport.cpp b/test/testclangimport.cpp
index 713af04e0..0d62da7ee 100644
--- a/test/testclangimport.cpp
+++ b/test/testclangimport.cpp
@@ -23,10 +23,9 @@
 #include "testsuite.h"
 
 #include <cstdint>
-#include <iosfwd>
 #include <list>
 #include <memory>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <string>
 #include <vector>
 
diff --git a/test/testclass.cpp b/test/testclass.cpp
index ca950e27b..010bd1b4f 100644
--- a/test/testclass.cpp
+++ b/test/testclass.cpp
@@ -24,9 +24,8 @@
 #include "testsuite.h"
 #include "tokenize.h"
 
-#include <iosfwd>
 #include <list>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <string>
 #include <vector>
 
diff --git a/test/testcmdlineparser.cpp b/test/testcmdlineparser.cpp
index efaa0b4d1..de30f3629 100644
--- a/test/testcmdlineparser.cpp
+++ b/test/testcmdlineparser.cpp
@@ -27,6 +27,7 @@
 #include "testsuite.h"
 #include "timer.h"
 
+#include <cstdio>
 #include <list>
 #include <set>
 #include <string>
diff --git a/test/testcondition.cpp b/test/testcondition.cpp
index 8adfbf054..f810d55ea 100644
--- a/test/testcondition.cpp
+++ b/test/testcondition.cpp
@@ -25,9 +25,8 @@
 #include "testsuite.h"
 #include "tokenize.h"
 
-#include <iosfwd>
 #include <map>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <string>
 #include <utility>
 #include <vector>
diff --git a/test/testconstructors.cpp b/test/testconstructors.cpp
index 88516f2da..41c475a97 100644
--- a/test/testconstructors.cpp
+++ b/test/testconstructors.cpp
@@ -24,9 +24,8 @@
 #include "testsuite.h"
 #include "tokenize.h"
 
-#include <iosfwd>
 #include <list>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <string>
 
 
diff --git a/test/testexceptionsafety.cpp b/test/testexceptionsafety.cpp
index d8f2074d9..964da3775 100644
--- a/test/testexceptionsafety.cpp
+++ b/test/testexceptionsafety.cpp
@@ -23,8 +23,7 @@
 #include "testsuite.h"
 #include "tokenize.h"
 
-#include <iosfwd>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 
 class TestExceptionSafety : public TestFixture {
 public:
diff --git a/test/testfunctions.cpp b/test/testfunctions.cpp
index 458198a7b..9d0d4ee49 100644
--- a/test/testfunctions.cpp
+++ b/test/testfunctions.cpp
@@ -24,9 +24,8 @@
 #include "testsuite.h"
 #include "tokenize.h"
 
-#include <iosfwd>
 #include <list>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <string>
 
 #include <tinyxml2.h>
diff --git a/test/testgarbage.cpp b/test/testgarbage.cpp
index 5d50e584e..8a112a074 100644
--- a/test/testgarbage.cpp
+++ b/test/testgarbage.cpp
@@ -24,9 +24,8 @@
 #include "token.h"
 #include "tokenize.h"
 
-#include <iosfwd>
 #include <list>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <string>
 
 
diff --git a/test/testimportproject.cpp b/test/testimportproject.cpp
index afbd0bea7..1d7bb8039 100644
--- a/test/testimportproject.cpp
+++ b/test/testimportproject.cpp
@@ -20,11 +20,10 @@
 #include "settings.h"
 #include "testsuite.h"
 
-#include <iosfwd>
 #include <list>
 #include <memory>
 #include <map>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <string>
 #include <vector>
 
diff --git a/test/testincompletestatement.cpp b/test/testincompletestatement.cpp
index 0a037d4c9..c124c49f4 100644
--- a/test/testincompletestatement.cpp
+++ b/test/testincompletestatement.cpp
@@ -22,9 +22,8 @@
 #include "testsuite.h"
 #include "tokenize.h"
 
-#include <iosfwd>
 #include <map>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <string>
 #include <utility>
 #include <vector>
diff --git a/test/testio.cpp b/test/testio.cpp
index 5bc7f7524..ab200834a 100644
--- a/test/testio.cpp
+++ b/test/testio.cpp
@@ -25,8 +25,7 @@
 #include "testsuite.h"
 #include "tokenize.h"
 
-#include <iosfwd>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 
 
 class TestIO : public TestFixture {
diff --git a/test/testleakautovar.cpp b/test/testleakautovar.cpp
index 6703a6a1c..dcbc11732 100644
--- a/test/testleakautovar.cpp
+++ b/test/testleakautovar.cpp
@@ -24,9 +24,8 @@
 #include "testsuite.h"
 #include "tokenize.h"
 
-#include <iosfwd>
 #include <map>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <string>
 #include <utility>
 #include <vector>
diff --git a/test/testlibrary.cpp b/test/testlibrary.cpp
index 6d5ca08c5..5e7cd8153 100644
--- a/test/testlibrary.cpp
+++ b/test/testlibrary.cpp
@@ -26,9 +26,8 @@
 #include "tokenize.h"
 #include "tokenlist.h"
 
-#include <iosfwd>
 #include <map>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <string>
 #include <unordered_map>
 #include <vector>
diff --git a/test/testmemleak.cpp b/test/testmemleak.cpp
index 1dd2b8d22..a7a6640b3 100644
--- a/test/testmemleak.cpp
+++ b/test/testmemleak.cpp
@@ -24,10 +24,9 @@
 #include "token.h"
 #include "tokenize.h"
 
-#include <iosfwd>
 #include <list>
 #include <memory>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <string>
 
 class TestMemleakInClass;
diff --git a/test/testnullpointer.cpp b/test/testnullpointer.cpp
index 40f6e1d30..e0475c95b 100644
--- a/test/testnullpointer.cpp
+++ b/test/testnullpointer.cpp
@@ -26,10 +26,9 @@
 #include "token.h"
 #include "tokenize.h"
 
-#include <iosfwd>
 #include <list>
 #include <map>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <string>
 #include <unordered_map>
 #include <utility>
diff --git a/test/testother.cpp b/test/testother.cpp
index 3f5062645..844c6117c 100644
--- a/test/testother.cpp
+++ b/test/testother.cpp
@@ -26,9 +26,8 @@
 #include "testsuite.h"
 #include "tokenize.h"
 
-#include <iosfwd>
 #include <map>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <string>
 #include <unordered_map>
 #include <utility>
diff --git a/test/testpostfixoperator.cpp b/test/testpostfixoperator.cpp
index 60a06615d..e4a890dd8 100644
--- a/test/testpostfixoperator.cpp
+++ b/test/testpostfixoperator.cpp
@@ -23,8 +23,7 @@
 #include "testsuite.h"
 #include "tokenize.h"
 
-#include <iosfwd>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 
 class TestPostfixOperator : public TestFixture {
 public:
diff --git a/test/testpreprocessor.cpp b/test/testpreprocessor.cpp
index 1b19770bb..887c0a4f6 100644
--- a/test/testpreprocessor.cpp
+++ b/test/testpreprocessor.cpp
@@ -30,12 +30,11 @@
 
 #include <atomic>
 #include <cstring>
-#include <iosfwd>
 #include <list>
 #include <map>
 #include <memory>
 #include <set>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <string>
 #include <vector>
 
diff --git a/test/testprocessexecutor.cpp b/test/testprocessexecutor.cpp
index ccb5cf078..7030c540c 100644
--- a/test/testprocessexecutor.cpp
+++ b/test/testprocessexecutor.cpp
@@ -21,11 +21,11 @@
 #include "settings.h"
 #include "testsuite.h"
 #include "testutils.h"
+#include "timer.h"
 
 #include <algorithm>
 #include <cstddef>
 #include <map>
-#include <ostream>
 #include <sstream>
 #include <string>
 #include <utility>
diff --git a/test/testsimplifytemplate.cpp b/test/testsimplifytemplate.cpp
index 52c4f58f9..a995c8a48 100644
--- a/test/testsimplifytemplate.cpp
+++ b/test/testsimplifytemplate.cpp
@@ -27,8 +27,7 @@
 #include "tokenlist.h"
 
 #include <cstring>
-#include <iosfwd>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <string>
 #include <vector>
 
diff --git a/test/testsimplifytokens.cpp b/test/testsimplifytokens.cpp
index e6cab9321..efe16cc4b 100644
--- a/test/testsimplifytokens.cpp
+++ b/test/testsimplifytokens.cpp
@@ -24,8 +24,7 @@
 #include "token.h"
 #include "tokenize.h"
 
-#include <istream>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <string>
 
 
diff --git a/test/testsimplifyusing.cpp b/test/testsimplifyusing.cpp
index 775daf39b..02cc510e4 100644
--- a/test/testsimplifyusing.cpp
+++ b/test/testsimplifyusing.cpp
@@ -24,8 +24,7 @@
 #include "token.h"
 #include "tokenize.h"
 
-#include <iosfwd>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <string>
 
 
diff --git a/test/testsizeof.cpp b/test/testsizeof.cpp
index 9f9b6d0b1..cc832ccaf 100644
--- a/test/testsizeof.cpp
+++ b/test/testsizeof.cpp
@@ -22,9 +22,8 @@
 #include "testsuite.h"
 #include "tokenize.h"
 
-#include <iosfwd>
 #include <map>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <string>
 #include <utility>
 #include <vector>
diff --git a/test/teststl.cpp b/test/teststl.cpp
index 88bdfa89d..1b560132a 100644
--- a/test/teststl.cpp
+++ b/test/teststl.cpp
@@ -24,8 +24,7 @@
 #include "tokenize.h"
 
 #include <cstddef>
-#include <iosfwd>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <string>
 
 
diff --git a/test/teststring.cpp b/test/teststring.cpp
index f1347c8aa..f7ddeb128 100644
--- a/test/teststring.cpp
+++ b/test/teststring.cpp
@@ -23,8 +23,7 @@
 #include "testsuite.h"
 #include "tokenize.h"
 
-#include <iosfwd>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 
 
 class TestString : public TestFixture {
diff --git a/test/testsummaries.cpp b/test/testsummaries.cpp
index a26636562..91b07c173 100644
--- a/test/testsummaries.cpp
+++ b/test/testsummaries.cpp
@@ -22,8 +22,7 @@
 #include "testsuite.h"
 #include "tokenize.h"
 
-#include <iosfwd>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <string>
 
 
diff --git a/test/testsuppressions.cpp b/test/testsuppressions.cpp
index 40b8be72f..86590d859 100644
--- a/test/testsuppressions.cpp
+++ b/test/testsuppressions.cpp
@@ -31,11 +31,10 @@
 #include <cstddef>
 #include <cstring>
 #include <functional>
-#include <iosfwd>
 #include <list>
 #include <map>
 #include <memory>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <string>
 #include <utility>
 #include <vector>
diff --git a/test/testthreadexecutor.cpp b/test/testthreadexecutor.cpp
index ac98b0da3..85a477e8b 100644
--- a/test/testthreadexecutor.cpp
+++ b/test/testthreadexecutor.cpp
@@ -21,11 +21,11 @@
 #include "testsuite.h"
 #include "testutils.h"
 #include "threadexecutor.h"
+#include "timer.h"
 
 #include <algorithm>
 #include <cstddef>
 #include <map>
-#include <ostream>
 #include <sstream>
 #include <string>
 #include <utility>
diff --git a/test/testtoken.cpp b/test/testtoken.cpp
index ea94f140d..81dc56f7f 100644
--- a/test/testtoken.cpp
+++ b/test/testtoken.cpp
@@ -25,8 +25,7 @@
 #include "valueflow.h"
 
 #include <algorithm>
-#include <iosfwd>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <string>
 #include <vector>
 
diff --git a/test/testtokenlist.cpp b/test/testtokenlist.cpp
index 314d34b7a..229d5baa3 100644
--- a/test/testtokenlist.cpp
+++ b/test/testtokenlist.cpp
@@ -21,8 +21,7 @@
 #include "token.h"
 #include "tokenlist.h"
 
-#include <iosfwd>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <string>
 
 class TestTokenList : public TestFixture {
diff --git a/test/testtokenrange.cpp b/test/testtokenrange.cpp
index 6cdda8c19..0a30f778a 100644
--- a/test/testtokenrange.cpp
+++ b/test/testtokenrange.cpp
@@ -27,7 +27,6 @@
 #include <algorithm>
 #include <iterator>
 #include <list>
-#include <ostream>
 #include <sstream>
 #include <string>
 
diff --git a/test/testtype.cpp b/test/testtype.cpp
index cdd0307ce..820a9d49e 100644
--- a/test/testtype.cpp
+++ b/test/testtype.cpp
@@ -24,8 +24,7 @@
 #include "testsuite.h"
 #include "tokenize.h"
 
-#include <iosfwd>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <string>
 
 class TestType : public TestFixture {
diff --git a/test/testunusedprivfunc.cpp b/test/testunusedprivfunc.cpp
index 837b8869f..02c1dec08 100644
--- a/test/testunusedprivfunc.cpp
+++ b/test/testunusedprivfunc.cpp
@@ -23,9 +23,8 @@
 #include "testsuite.h"
 #include "tokenize.h"
 
-#include <iosfwd>
 #include <map>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <string>
 #include <utility>
 #include <vector>
diff --git a/test/testunusedvar.cpp b/test/testunusedvar.cpp
index c020684f7..ac9acbbc3 100644
--- a/test/testunusedvar.cpp
+++ b/test/testunusedvar.cpp
@@ -23,9 +23,8 @@
 #include "testsuite.h"
 #include "tokenize.h"
 
-#include <iosfwd>
 #include <list>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <string>
 
 class TestUnusedVar : public TestFixture {
diff --git a/test/testutils.h b/test/testutils.h
index 0c87f7236..b7eb9b58b 100644
--- a/test/testutils.h
+++ b/test/testutils.h
@@ -27,10 +27,8 @@
 #include "tokenlist.h"
 
 #include <cstdio>
-#include <iosfwd>
 #include <list>
-#include <ostream>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <string>
 
 class Token;
diff --git a/test/testvaarg.cpp b/test/testvaarg.cpp
index 0b57e1357..a59d08972 100644
--- a/test/testvaarg.cpp
+++ b/test/testvaarg.cpp
@@ -23,8 +23,7 @@
 #include "testsuite.h"
 #include "tokenize.h"
 
-#include <iosfwd>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 
 class TestVaarg : public TestFixture {
 public:
diff --git a/test/testvalueflow.cpp b/test/testvalueflow.cpp
index 429b1fa99..11ab7e6aa 100644
--- a/test/testvalueflow.cpp
+++ b/test/testvalueflow.cpp
@@ -34,7 +34,6 @@
 #include <list>
 #include <map>
 #include <memory>
-#include <ostream>
 #include <set>
 #include <sstream>
 #include <string>
diff --git a/test/testvarid.cpp b/test/testvarid.cpp
index 992d8ec3e..ca589b050 100644
--- a/test/testvarid.cpp
+++ b/test/testvarid.cpp
@@ -24,8 +24,7 @@
 #include "token.h"
 #include "tokenize.h"
 
-#include <iosfwd>
-#include <sstream>
+#include <sstream> // IWYU pragma: keep
 #include <string>
 
 struct InternalError;