diff --git a/lib/checkunusedvar.cpp b/lib/checkunusedvar.cpp
index 59e1800f1..07c914791 100644
--- a/lib/checkunusedvar.cpp
+++ b/lib/checkunusedvar.cpp
@@ -940,6 +940,7 @@ void CheckUnusedVar::checkFunctionVariableUsage()
         for (Variables::VariableMap::const_iterator it = variables.varUsage().begin(); it != variables.varUsage().end(); ++it) {
             const Variables::VariableUsage &usage = it->second;
             const std::string &varname = usage._name->str();
+            const Variable* var = symbolDatabase->getVariableFromVarId(it->first);
 
             // variable has been marked as unused so ignore it
             if (usage._name->isUnused())
@@ -961,7 +962,7 @@ void CheckUnusedVar::checkFunctionVariableUsage()
                 unusedVariableError(usage._name, varname);
 
             // variable has not been written but has been modified
-            else if (usage._modified && !usage._write && !usage._allocateMemory)
+            else if (usage._modified && !usage._write && !usage._allocateMemory && !Token::simpleMatch(var->typeStartToken(), "std ::"))
                 unassignedVariableError(usage._name, varname);
 
             // variable has been written but not read
@@ -969,7 +970,7 @@ void CheckUnusedVar::checkFunctionVariableUsage()
                 unreadVariableError(usage._name, varname);
 
             // variable has been read but not written
-            else if (!usage._write && !usage._allocateMemory)
+            else if (!usage._write && !usage._allocateMemory && !Token::simpleMatch(var->typeStartToken(), "std ::"))
                 unassignedVariableError(usage._name, varname);
         }
     }
diff --git a/test/testunusedvar.cpp b/test/testunusedvar.cpp
index 174f383bf..7b449e4ea 100644
--- a/test/testunusedvar.cpp
+++ b/test/testunusedvar.cpp
@@ -3087,10 +3087,10 @@ private:
         ASSERT_EQUALS("[test.cpp:2]: (style) Variable 's' is assigned a value that is never used\n", errout.str());
 
         functionVariableUsage("std::string foo() {\n"
-                              "    std::string s;\n"
+                              "    std::string s;\n" // Class instances are initialized. Assignement is not necessary
                               "    return s;\n"
                               "}\n");
-        ASSERT_EQUALS("[test.cpp:2]: (style) Variable 's' is not assigned a value\n", errout.str());
+        ASSERT_EQUALS("", errout.str());
 
         functionVariableUsage("std::string foo() {\n"
                               "    std::string s = \"foo\";\n"