diff --git a/lib/checkbufferoverrun.cpp b/lib/checkbufferoverrun.cpp
index b35f2eddb..9aa809b34 100644
--- a/lib/checkbufferoverrun.cpp
+++ b/lib/checkbufferoverrun.cpp
@@ -707,7 +707,7 @@ void CheckBufferOverrun::checkFunctionParameter(const Token &tok, unsigned int p
                         Token::Match(ftok, "%var% --"))
                         break;
 
-                    if (Token::Match(ftok->previous(), "[=+-*/;{}] %var% [ %num% ]"))
+                    if ((Token::Match(ftok->previous(), "[=;{}]") || ftok->previous()->isOp()) && Token::Match(ftok, "%var% [ %num% ]"))
                     {
                         const MathLib::bigint index = MathLib::toLongNumber(ftok->strAt(2));
                         if (index >= 0 && arrayInfo.num[0] > 0 && index >= arrayInfo.num[0])
diff --git a/lib/checkmemoryleak.cpp b/lib/checkmemoryleak.cpp
index b54d3e766..9aa5df0b6 100644
--- a/lib/checkmemoryleak.cpp
+++ b/lib/checkmemoryleak.cpp
@@ -1492,7 +1492,7 @@ Token *CheckMemoryLeakInFunction::getcode(const Token *tok, std::list<const Toke
             {
                 addtoken(&rettail, tok, "use");
             }
-            else if (Token::Match(tok->previous(), "[;{}=(,+-*/] %varid% [", varid))
+            else if ((Token::Match(tok->previous(), "[;{}=(,]") || tok->previous()->isOp()) && Token::Match(tok, "%varid% [", varid))
             {
                 // warning is written for "dealloc ; use_ ;".
                 // but this use doesn't affect the leak-checking
diff --git a/lib/token.h b/lib/token.h
index 728e6f8d6..69d96e918 100644
--- a/lib/token.h
+++ b/lib/token.h
@@ -153,12 +153,17 @@ public:
     {
         _isNumber = number;
     }
+    bool isArithmeticalOp() const
+    {
+        return (this && (_str=="<<" || _str==">>" || (_str.size()==1 && _str.find_first_of("+-*/%") != std::string::npos)));
+    }
     bool isOp() const
     {
         if (!this)
             return false;
 
-        return (_str == "&&" ||
+        return (isArithmeticalOp() ||
+                _str == "&&" ||
                 _str == "||" ||
                 _str == "==" ||
                 _str == "!=" ||
@@ -166,13 +171,12 @@ public:
                 _str == "<=" ||
                 _str == ">"  ||
                 _str == ">=" ||
-                _str == "<<" ||
-                _str == ">>" ||
-                Token::Match(this, "[+-*/%&|^~!]"));
+                (_str.size() == 1 && _str.find_first_of("&|^~!") != std::string::npos));
     }
     bool isExtendedOp() const
     {
-        return isOp() || Match(this, "[,[]()?:]");
+        return isOp() || 
+               (this && _str.size() == 1 && _str.find_first_of(",[]()?:") != std::string::npos);
     }
     bool isBoolean() const
     {
diff --git a/lib/tokenize.cpp b/lib/tokenize.cpp
index 747dc0c56..4c46e11ff 100644
--- a/lib/tokenize.cpp
+++ b/lib/tokenize.cpp
@@ -2075,15 +2075,9 @@ bool Tokenizer::tokenize(std::istream &code,
     // Combine "- %num%" ..
     for (Token *tok = _tokens; tok; tok = tok->next())
     {
-        if (Token::Match(tok, "[([+-*/=,] - %num%") && tok->strAt(2)[0] != '-')
+        if (Token::Match(tok, "%any% - %num%") && (tok->isOp() || Token::Match(tok, "?|:|,|(|[|=|return|case")))
         {
-            tok->next()->str(std::string("-") + tok->strAt(2));
-            tok->next()->deleteNext();
-        }
-
-        if (Token::Match(tok, "return|case - %num%") && tok->strAt(2)[0] != '-')
-        {
-            tok->next()->str(std::string("-") + tok->strAt(2));
+            tok->next()->str("-" + tok->strAt(2));
             tok->next()->deleteNext();
         }
     }
diff --git a/test/testsimplifytokens.cpp b/test/testsimplifytokens.cpp
index e24d094ae..53cdf121f 100644
--- a/test/testsimplifytokens.cpp
+++ b/test/testsimplifytokens.cpp
@@ -3772,7 +3772,7 @@ private:
 
         const char expected[] =
             "; "
-            "int a [ ice_or < is_int < int > :: value , is_int < UDT > :: value > :: value ? 1 : - 1 ] ; "
+            "int a [ ice_or < is_int < int > :: value , is_int < UDT > :: value > :: value ? 1 : -1 ] ; "
             "int a1 [ N ] ; "
             "int a2 [ N ] [ M ] ; "
             "int t ; "