diff --git a/lib/checkboost.h b/lib/checkboost.h
index 912120b06..9c3ed6e89 100644
--- a/lib/checkboost.h
+++ b/lib/checkboost.h
@@ -45,6 +45,9 @@ public:
 
     /** Simplified checks. The token list is simplified. */
     void runSimplifiedChecks(const Tokenizer *tokenizer, const Settings *settings, ErrorLogger *errorLogger) {
+        if (!tokenizer->isCPP())
+            return;
+
         CheckBoost checkBoost(tokenizer, settings, errorLogger);
 
         checkBoost.checkBoostForeachModification();
diff --git a/lib/checkclass.h b/lib/checkclass.h
index 6ed588a8f..09e36a4ef 100644
--- a/lib/checkclass.h
+++ b/lib/checkclass.h
@@ -44,6 +44,9 @@ public:
 
     /** @brief Run checks on the normal token list */
     void runChecks(const Tokenizer *tokenizer, const Settings *settings, ErrorLogger *errorLogger) {
+        if (tokenizer->isC())
+            return;
+
         CheckClass checkClass(tokenizer, settings, errorLogger);
 
         // can't be a simplified check .. the 'sizeof' is used.
@@ -52,6 +55,9 @@ public:
 
     /** @brief Run checks on the simplified token list */
     void runSimplifiedChecks(const Tokenizer *tokenizer, const Settings *settings, ErrorLogger *errorLogger) {
+        if (tokenizer->isC())
+            return;
+
         CheckClass checkClass(tokenizer, settings, errorLogger);
 
         // Coding style checks
diff --git a/lib/checkexceptionsafety.h b/lib/checkexceptionsafety.h
index a08c2f4b9..332280047 100644
--- a/lib/checkexceptionsafety.h
+++ b/lib/checkexceptionsafety.h
@@ -53,6 +53,9 @@ public:
 
     /** Checks that uses the simplified token list */
     void runSimplifiedChecks(const Tokenizer *tokenizer, const Settings *settings, ErrorLogger *errorLogger) {
+        if (tokenizer->isC())
+            return;
+
         CheckExceptionSafety checkExceptionSafety(tokenizer, settings, errorLogger);
         checkExceptionSafety.destructors();
         checkExceptionSafety.deallocThrow();
diff --git a/lib/checkmemoryleak.h b/lib/checkmemoryleak.h
index 09eafd262..022459aea 100644
--- a/lib/checkmemoryleak.h
+++ b/lib/checkmemoryleak.h
@@ -363,7 +363,7 @@ public:
 
     void runSimplifiedChecks(const Tokenizer *tokenizr, const Settings *settings, ErrorLogger *errLog) {
         // Don't use these check for Java and C# programs..
-        if (tokenizr->isJavaOrCSharp())
+        if (!tokenizr->isCPP())
             return;
 
         CheckMemoryLeakInClass checkMemoryLeak(tokenizr, settings, errLog);
diff --git a/lib/checkother.cpp b/lib/checkother.cpp
index 415648290..b85bbc965 100644
--- a/lib/checkother.cpp
+++ b/lib/checkother.cpp
@@ -1871,7 +1871,7 @@ void CheckOther::variableScopeError(const Token *tok, const std::string &varname
 //---------------------------------------------------------------------------
 void CheckOther::checkConstantFunctionParameter()
 {
-    if (!_settings->isEnabled("performance"))
+    if (!_settings->isEnabled("performance") || _tokenizer->isC())
         return;
 
     const SymbolDatabase * const symbolDatabase = _tokenizer->getSymbolDatabase();
@@ -3276,7 +3276,7 @@ In most scenarios, "const A & a = getA()" will be more efficient.
 */
 void CheckOther::checkRedundantCopy()
 {
-    if (!_settings->isEnabled("performance"))
+    if (!_settings->isEnabled("performance") || _tokenizer->isC())
         return;
 
     const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
diff --git a/lib/checkpostfixoperator.h b/lib/checkpostfixoperator.h
index b8e96aa41..8d47aba39 100644
--- a/lib/checkpostfixoperator.h
+++ b/lib/checkpostfixoperator.h
@@ -44,6 +44,9 @@ public:
     { }
 
     void runSimplifiedChecks(const Tokenizer *tokenizer, const Settings *settings, ErrorLogger *errorLogger) {
+        if (tokenizer->isC())
+            return;
+
         CheckPostfixOperator checkPostfixOperator(tokenizer, settings, errorLogger);
         checkPostfixOperator.postfixOperator();
     }
diff --git a/lib/checkstl.cpp b/lib/checkstl.cpp
index 5ea718ba4..6aa3239d8 100644
--- a/lib/checkstl.cpp
+++ b/lib/checkstl.cpp
@@ -1072,9 +1072,6 @@ static bool isLocal(const SymbolDatabase* symbolDatabase, unsigned int varid)
 
 void CheckStl::string_c_str()
 {
-    if (!_tokenizer->isCPP())
-        return;
-
     const SymbolDatabase* symbolDatabase = _tokenizer->getSymbolDatabase();
 
     // Find all functions that take std::string as argument
@@ -1238,9 +1235,6 @@ static bool hasArrayEndParen(const Token *tok1)
 //---------------------------------------------------------------------------
 void CheckStl::checkAutoPointer()
 {
-    if (!_tokenizer->isCPP())
-        return;
-
     std::set<unsigned int> autoPtrVarId;
     static const char STL_CONTAINER_LIST[] = "array|bitset|deque|list|forward_list|map|multimap|multiset|priority_queue|queue|set|stack|vector|hash_map|hash_multimap|hash_set|unordered_map|unordered_multimap|unordered_set|unordered_multiset|basic_string";
 
diff --git a/lib/checkstl.h b/lib/checkstl.h
index c667f2b42..7cd5cdc3c 100644
--- a/lib/checkstl.h
+++ b/lib/checkstl.h
@@ -45,6 +45,9 @@ public:
 
     /** Simplified checks. The token list is simplified. */
     void runSimplifiedChecks(const Tokenizer *tokenizer, const Settings *settings, ErrorLogger *errorLogger) {
+        if (!tokenizer->isCPP())
+            return;
+
         CheckStl checkStl(tokenizer, settings, errorLogger);
 
         checkStl.stlOutOfBounds();
diff --git a/lib/tokenize.cpp b/lib/tokenize.cpp
index 73c44f81a..b3f963287 100644
--- a/lib/tokenize.cpp
+++ b/lib/tokenize.cpp
@@ -2075,6 +2075,9 @@ bool Tokenizer::hasComplicatedSyntaxErrorsInTemplates()
 
 void Tokenizer::simplifyDefaultAndDeleteInsideClass()
 {
+    if (isC())
+        return;
+
     // Remove "= default|delete" inside class|struct definitions
     // Todo: Remove it if it is used "externally" too.
     for (Token *tok = list.front(); tok; tok = tok->next()) {
@@ -2487,6 +2490,9 @@ void Tokenizer::simplifyLabelsCaseDefault()
 
 void Tokenizer::simplifyTemplates()
 {
+    if (isC())
+        return;
+
     for (Token *tok = list.front(); tok; tok = tok->next()) {
         // #2648 - simple fix for sizeof used as template parameter
         // TODO: this is a bit hardcoded. make a bit more generic
@@ -6640,6 +6646,9 @@ bool Tokenizer::simplifyRedundantParenthesis()
 
 void Tokenizer::simplifyReference()
 {
+    if (isC())
+        return;
+
     for (Token *tok = list.front(); tok; tok = tok->next()) {
         // starting executable scope..
         if (Token::Match(tok, ") const| {")) {
@@ -7432,6 +7441,9 @@ void Tokenizer::simplifyEnum()
 
 void Tokenizer::simplifyStd()
 {
+    if (isC())
+        return;
+
     std::set<std::string> f;
     f.insert("strcat");
     f.insert("strcpy");
@@ -7946,6 +7958,9 @@ void Tokenizer::simplifyComma()
 
 void Tokenizer::removeExceptionSpecifications()
 {
+    if (isC())
+        return;
+
     for (Token* tok = list.front(); tok; tok = tok->next()) {
         if (Token::Match(tok, ") const| throw (")) {
             if (tok->next()->str() == "const") {
@@ -9063,6 +9078,9 @@ void Tokenizer::deleteSymbolDatabase()
 
 void Tokenizer::simplifyOperatorName()
 {
+    if (isC())
+        return;
+
     for (Token *tok = list.front(); tok; tok = tok->next()) {
         if (tok->str() == "operator") {
             // operator op
@@ -9117,6 +9135,9 @@ void Tokenizer::simplifyOperatorName()
 // remove unnecessary member qualification..
 void Tokenizer::removeUnnecessaryQualification()
 {
+    if (isC())
+        return;
+
     std::vector<Space> classInfo;
     for (Token *tok = list.front(); tok; tok = tok->next()) {
         if (Token::Match(tok, "class|struct|namespace %type% :|{") &&