diff --git a/lib/checkother.cpp b/lib/checkother.cpp
index ef4a14fe2..953a1ef82 100644
--- a/lib/checkother.cpp
+++ b/lib/checkother.cpp
@@ -2346,7 +2346,7 @@ void CheckOther::checkDuplicateExpression()
             continue;
 
         for (const Token *tok = scope->classStart; tok && tok != scope->classStart->link(); tok = tok->next()) {
-            if (Token::Match(tok, "=|%op%|return|(|&&|%oror% %var% &&|%oror%|==|!=|<=|>=|<|>|-|%or% %var% )|&&|%oror%|;") &&
+            if (Token::Match(tok, ",|=|return|(|&&|%oror% %var% &&|%oror%|==|!=|<=|>=|<|>|-|%or% %var% )|&&|%oror%|;") &&
                 tok->strAt(1) == tok->strAt(3)) {
                 // float == float and float != float are valid NaN checks
                 if (Token::Match(tok->tokAt(2), "==|!=") && tok->next()->varId()) {
@@ -2358,7 +2358,7 @@ void CheckOther::checkDuplicateExpression()
                 }
 
                 duplicateExpressionError(tok->next(), tok->tokAt(3), tok->strAt(2));
-            } else if (Token::Match(tok, "=|%op%|return|(|&&|%oror% %var% . %var% &&|%oror%|==|!=|<=|>=|<|>|-|%or% %var% . %var% )|&&|%oror%") &&
+            } else if (Token::Match(tok, ",|=|return|(|&&|%oror% %var% . %var% &&|%oror%|==|!=|<=|>=|<|>|-|%or% %var% . %var% )|&&|%oror%") &&
                        tok->strAt(1) == tok->strAt(5) && tok->strAt(3) == tok->strAt(7)) {
                 duplicateExpressionError(tok->next(), tok->tokAt(6), tok->strAt(4));
             }
diff --git a/lib/tokenize.cpp b/lib/tokenize.cpp
index 2034af759..a47bf43a4 100644
--- a/lib/tokenize.cpp
+++ b/lib/tokenize.cpp
@@ -4994,9 +4994,9 @@ void Tokenizer::simplifyCompoundAssignment()
             // Is current token at a compound assignment: +=|-=|.. ?
             const std::string &str = tok->str();
             std::string op;  // operator used in assignment
-            if (str.size() == 2 && str[1] == '=' && str.find_first_of("+-*/%&|^")==0)
+            if (tok->isAssignmentOp() && str.size() == 2)
                 op = str.substr(0, 1);
-            else if (str=="<<=" || str==">>=")
+            else if (tok->isAssignmentOp() && str.size() == 3)
                 op = str.substr(0, 2);
             else {
                 tok = tok1;
@@ -5029,7 +5029,7 @@ void Tokenizer::simplifyCompoundAssignment()
                             break;
                         }
 
-                        someOperator |= bool(tok2->isArithmeticalOp() || (tok2->str() == "?"));
+                        someOperator |= (tok2->isOp() || (tok2->str() == "?"));
                     }
                 }
 
diff --git a/test/testother.cpp b/test/testother.cpp
index b0af1fca7..5fe2f708c 100644
--- a/test/testother.cpp
+++ b/test/testother.cpp
@@ -3428,7 +3428,7 @@ private:
         ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:2]: (style) Same expression on both sides of '&&'.\n", errout.str());
 
         check("void foo() {\n"
-              "    a = a + b && b;\n"
+              "    f(a,b && b);\n"
               "}");
         ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:2]: (style) Same expression on both sides of '&&'.\n", errout.str());
     }
diff --git a/test/testtokenize.cpp b/test/testtokenize.cpp
index bb5aab0c4..5597d66b6 100644
--- a/test/testtokenize.cpp
+++ b/test/testtokenize.cpp
@@ -5665,6 +5665,10 @@ private:
         // #2714 - wrong simplification of "a += b?c:d;"
         ASSERT_EQUALS("; a = a + ( b ? c : d ) ;", tokenizeAndStringify("; a+=b?c:d;"));
         ASSERT_EQUALS("; a = a * ( b + 1 ) ;", tokenizeAndStringify("; a*=b+1;"));
+
+        ASSERT_EQUALS("; a = a + ( b && c ) ;", tokenizeAndStringify("; a+=b&&c;"));
+        ASSERT_EQUALS("; a = a * ( b || c ) ;", tokenizeAndStringify("; a*=b||c;"));
+        ASSERT_EQUALS("; a = a | ( b == c ) ;", tokenizeAndStringify("; a|=b==c;"));
     }
 
     void simplifyAssignmentInFunctionCall() {