diff --git a/lib/astutils.cpp b/lib/astutils.cpp
index 1c8ded8a1..f998ec84f 100644
--- a/lib/astutils.cpp
+++ b/lib/astutils.cpp
@@ -227,7 +227,7 @@ bool precedes(const Token * tok1, const Token * tok2)
     return tok1->index() < tok2->index();
 }
 
-static bool isAliased(const Token * startTok, const Token * endTok, unsigned int varid)
+static bool isAliased(const Token * startTok, const Token * endTok, int varid)
 {
     for (const Token *tok = startTok; tok != endTok; tok = tok->next()) {
         if (Token::Match(tok, "= & %varid% ;", varid))
@@ -248,7 +248,7 @@ static bool isAliased(const Token * startTok, const Token * endTok, unsigned int
     return false;
 }
 
-static bool exprDependsOnThis(const Token *expr, unsigned int depth)
+static bool exprDependsOnThis(const Token *expr, int depth)
 {
     if (!expr)
         return false;
@@ -804,7 +804,7 @@ bool isReturnScope(const Token * const endToken)
     return false;
 }
 
-bool isVariableChangedByFunctionCall(const Token *tok, unsigned int varid, const Settings *settings, bool *inconclusive)
+bool isVariableChangedByFunctionCall(const Token *tok, int varid, const Settings *settings, bool *inconclusive)
 {
     if (!tok)
         return false;
@@ -846,7 +846,7 @@ bool isVariableChangedByFunctionCall(const Token *tok, const Settings *settings,
     }
 
     // goto start of function call and get argnr
-    unsigned int argnr = 0;
+    int argnr = 0;
     while (tok && !Token::Match(tok, "[;{}]")) {
         if (tok->str() == ",")
             ++argnr;
@@ -870,7 +870,7 @@ bool isVariableChangedByFunctionCall(const Token *tok, const Settings *settings,
     // Constructor call
     if (tok->variable() && tok->variable()->nameToken() == tok) {
         // Find constructor..
-        const unsigned int argCount = numberOfArguments(tok);
+        const int argCount = numberOfArguments(tok);
         const Scope *typeScope = tok->variable()->typeScope();
         if (typeScope) {
             for (const Function &function : typeScope->functionList) {
@@ -930,7 +930,7 @@ bool isVariableChangedByFunctionCall(const Token *tok, const Settings *settings,
     return arg && !arg->isConst() && arg->isReference();
 }
 
-bool isVariableChanged(const Token *start, const Token *end, const unsigned int varid, bool globalvar, const Settings *settings, bool cpp)
+bool isVariableChanged(const Token *start, const Token *end, const int varid, bool globalvar, const Settings *settings, bool cpp)
 {
     for (const Token *tok = start; tok != end; tok = tok->next()) {
         if (tok->varId() != varid) {
@@ -1017,7 +1017,7 @@ int numberOfArguments(const Token *start)
     return arguments;
 }
 
-static void getArgumentsRecursive(const Token *tok, std::vector<const Token *> *arguments, unsigned int depth)
+static void getArgumentsRecursive(const Token *tok, std::vector<const Token *> *arguments, int depth)
 {
     ++depth;
     if (!tok || depth >= 100)
@@ -1172,7 +1172,7 @@ static bool hasFunctionCall(const Token *tok)
     return hasFunctionCall(tok->astOperand1()) || hasFunctionCall(tok->astOperand2());
 }
 
-struct FwdAnalysis::Result FwdAnalysis::checkRecursive(const Token *expr, const Token *startToken, const Token *endToken, const std::set<unsigned int> &exprVarIds, bool local, bool inInnerClass)
+struct FwdAnalysis::Result FwdAnalysis::checkRecursive(const Token *expr, const Token *startToken, const Token *endToken, const std::set<int> &exprVarIds, bool local, bool inInnerClass)
 {
     // Parse the given tokens
     for (const Token *tok = startToken; tok != endToken; tok = tok->next()) {
@@ -1429,7 +1429,7 @@ bool FwdAnalysis::isGlobalData(const Token *expr) const
 FwdAnalysis::Result FwdAnalysis::check(const Token *expr, const Token *startToken, const Token *endToken)
 {
     // all variable ids in expr.
-    std::set<unsigned int> exprVarIds;
+    std::set<int> exprVarIds;
     bool local = true;
     bool unknownVarId = false;
     visitAstNodes(expr,
@@ -1526,7 +1526,7 @@ bool FwdAnalysis::possiblyAliased(const Token *expr, const Token *startToken) co
         if (Token::Match(tok, "%name% (") && !Token::Match(tok, "if|while|for")) {
             // Is argument passed by reference?
             const std::vector<const Token*> args = getArguments(tok);
-            for (unsigned int argnr = 0; argnr < args.size(); ++argnr) {
+            for (int argnr = 0; argnr < args.size(); ++argnr) {
                 if (!Token::Match(args[argnr], "%name%|.|::"))
                     continue;
                 if (tok->function() && tok->function()->getArgumentVar(argnr) && !tok->function()->getArgumentVar(argnr)->isReference() && !tok->function()->isConst())
diff --git a/lib/astutils.h b/lib/astutils.h
index 8b616adc5..75a7d3b4f 100644
--- a/lib/astutils.h
+++ b/lib/astutils.h
@@ -118,7 +118,7 @@ bool isReturnScope(const Token *endToken);
  * @param settings      program settings
  * @param inconclusive  pointer to output variable which indicates that the answer of the question is inconclusive
  */
-bool isVariableChangedByFunctionCall(const Token *tok, unsigned int varid, const Settings *settings, bool *inconclusive);
+bool isVariableChangedByFunctionCall(const Token *tok, int varid, const Settings *settings, bool *inconclusive);
 
 /** Is variable changed by function call?
  * In case the answer of the question is inconclusive, e.g. because the function declaration is not known
@@ -131,7 +131,7 @@ bool isVariableChangedByFunctionCall(const Token *tok, unsigned int varid, const
 bool isVariableChangedByFunctionCall(const Token *tok, const Settings *settings, bool *inconclusive);
 
 /** Is variable changed in block of code? */
-bool isVariableChanged(const Token *start, const Token *end, const unsigned int varid, bool globalvar, const Settings *settings, bool cpp);
+bool isVariableChanged(const Token *start, const Token *end, const int varid, bool globalvar, const Settings *settings, bool cpp);
 
 bool isVariableChanged(const Variable * var, const Settings *settings, bool cpp);
 
@@ -221,7 +221,7 @@ private:
     };
 
     struct Result check(const Token *expr, const Token *startToken, const Token *endToken);
-    struct Result checkRecursive(const Token *expr, const Token *startToken, const Token *endToken, const std::set<unsigned int> &exprVarIds, bool local, bool inInnerClass);
+    struct Result checkRecursive(const Token *expr, const Token *startToken, const Token *endToken, const std::set<int> &exprVarIds, bool local, bool inInnerClass);
 
     // Is expression a l-value global data?
     bool isGlobalData(const Token *expr) const;