diff --git a/cli/cmdlineparser.cpp b/cli/cmdlineparser.cpp
index 8c0853d51..9eb6550b1 100644
--- a/cli/cmdlineparser.cpp
+++ b/cli/cmdlineparser.cpp
@@ -22,6 +22,7 @@
 #include "path.h"
 #include "settings.h"
 #include "timer.h"
+#include "check.h"
 
 #include <algorithm>
 #include <iostream>
diff --git a/cli/pathmatch.cpp b/cli/pathmatch.cpp
index bcf300001..a4c97f814 100644
--- a/cli/pathmatch.cpp
+++ b/cli/pathmatch.cpp
@@ -18,7 +18,7 @@
 
 #include "pathmatch.h"
 #include <algorithm>
-#include <ctype.h>      // Borland: tolower
+#include <ctype.h>
 
 PathMatch::PathMatch(const std::vector<std::string> &masks, bool caseSensitive)
     : _masks(masks), _caseSensitive(caseSensitive)
diff --git a/lib/cppcheck.cpp b/lib/cppcheck.cpp
index c5d36ac5d..f2dabc3a6 100644
--- a/lib/cppcheck.cpp
+++ b/lib/cppcheck.cpp
@@ -19,6 +19,7 @@
 
 #include "preprocessor.h" // Preprocessor
 #include "tokenize.h" // Tokenizer
+#include "checkunusedfunctions.h"
 
 #include "check.h"
 #include "path.h"
diff --git a/lib/cppcheck.h b/lib/cppcheck.h
index 9cb608778..f833423ee 100644
--- a/lib/cppcheck.h
+++ b/lib/cppcheck.h
@@ -24,12 +24,13 @@
 #include "config.h"
 #include "settings.h"
 #include "errorlogger.h"
-#include "checkunusedfunctions.h"
 
 #include <string>
 #include <list>
 #include <istream>
 
+class Tokenizer;
+
 /// @addtogroup Core
 /// @{
 
diff --git a/lib/library.h b/lib/library.h
index d3b20c91b..9b4547e64 100644
--- a/lib/library.h
+++ b/lib/library.h
@@ -30,7 +30,6 @@
 #include <set>
 #include <string>
 #include <list>
-#include <algorithm>
 
 class TokenList;
 namespace tinyxml2 {
diff --git a/lib/symboldatabase.cpp b/lib/symboldatabase.cpp
index c0b3c5d3c..9196cec63 100644
--- a/lib/symboldatabase.cpp
+++ b/lib/symboldatabase.cpp
@@ -25,7 +25,7 @@
 #include "errorlogger.h"
 
 #include <string>
-#include <sstream>
+#include <ostream>
 #include <climits>
 #include <iostream>
 
diff --git a/lib/symboldatabase.h b/lib/symboldatabase.h
index 06cd5f6d3..cc806b813 100644
--- a/lib/symboldatabase.h
+++ b/lib/symboldatabase.h
@@ -24,7 +24,6 @@
 #include <string>
 #include <list>
 #include <vector>
-#include <deque>
 #include <set>
 #include <algorithm>
 
diff --git a/lib/templatesimplifier.cpp b/lib/templatesimplifier.cpp
index 3e9715e91..3ca844932 100644
--- a/lib/templatesimplifier.cpp
+++ b/lib/templatesimplifier.cpp
@@ -19,7 +19,6 @@
 #include "templatesimplifier.h"
 #include "mathlib.h"
 #include "token.h"
-#include "tokenlist.h"
 #include "tokenize.h"
 #include "errorlogger.h"
 #include "settings.h"
diff --git a/lib/token.cpp b/lib/token.cpp
index 6562e2a84..47399c22c 100644
--- a/lib/token.cpp
+++ b/lib/token.cpp
@@ -29,6 +29,7 @@
 #include <sstream>
 #include <map>
 #include <stack>
+#include <algorithm>
 
 bool Token::_isCPP = true;
 
diff --git a/lib/valueflow.cpp b/lib/valueflow.cpp
index c1e579837..41f906329 100644
--- a/lib/valueflow.cpp
+++ b/lib/valueflow.cpp
@@ -24,7 +24,7 @@
 #include "token.h"
 #include "tokenlist.h"
 
-#include <iostream>
+//#include <iostream>
 #include <stack>
 
 
diff --git a/test/testcppcheck.cpp b/test/testcppcheck.cpp
index cfe227bea..f74a83532 100644
--- a/test/testcppcheck.cpp
+++ b/test/testcppcheck.cpp
@@ -21,6 +21,7 @@
 #include "cppcheckexecutor.h"
 #include "testsuite.h"
 #include "path.h"
+#include "check.h"
 
 #include <algorithm>
 #include <list>