diff --git a/lib/checkbool.cpp b/lib/checkbool.cpp
index 48455a8ab..cf902c49a 100644
--- a/lib/checkbool.cpp
+++ b/lib/checkbool.cpp
@@ -380,7 +380,7 @@ static bool isNonBoolLHSExpr(const Token *tok)
             nonBoolExpr = true;
         else if (tok->isArithmeticalOp())
             nonBoolExpr = true;
-        else if (tok->str() == "!" || tok->isComparisonOp())
+        else if (tok->isComparisonOp() || (tok->str() == "!" && tok->previous()->str()=="("))
             return false;
         else if (indentlevel == 0 && Token::Match(tok,"[;{}=?:&|^,]"))
             break;
diff --git a/test/testbool.cpp b/test/testbool.cpp
index ec60f7a1d..4ee175ba1 100644
--- a/test/testbool.cpp
+++ b/test/testbool.cpp
@@ -306,6 +306,9 @@ private:
               "  if (error == ABC) { }\n"
               "}");
         ASSERT_EQUALS("", errout.str());
+
+		check("int f() { return !a+b<c; }");
+		ASSERT_EQUALS("",errout.str());
     }
 
     void comparisonOfBoolExpressionWithInt2() {