diff --git a/lib/checkclass.cpp b/lib/checkclass.cpp
index 1c9122458..a581df4a8 100644
--- a/lib/checkclass.cpp
+++ b/lib/checkclass.cpp
@@ -340,11 +340,14 @@ void CheckClass::copyconstructors()
             }
             if (!funcCopyCtor || funcCopyCtor->isDefault()) {
                 bool unknown = false;
-                if (!isNonCopyable(scope, &unknown))
+                if (!isNonCopyable(scope, &unknown) && !unknown)
                     noCopyConstructorError(scope, funcCopyCtor, allocatedVars.begin()->second, unknown);
             }
-            if (!funcOperatorEq || funcOperatorEq->isDefault())
-                noOperatorEqError(scope, funcOperatorEq, allocatedVars.begin()->second);
+            if (!funcOperatorEq || funcOperatorEq->isDefault()) {
+                bool unknown = false;
+                if (!isNonCopyable(scope, &unknown) && !unknown)
+                    noOperatorEqError(scope, funcOperatorEq, allocatedVars.begin()->second, unknown);
+            }
             if (!funcDestructor || funcDestructor->isDefault()) {
                 const Token * mustDealloc = nullptr;
                 for (std::map<unsigned int, const Token*>::const_iterator it = allocatedVars.begin(); it != allocatedVars.end(); ++it) {
@@ -452,9 +455,9 @@ void CheckClass::noCopyConstructorError(const Scope *scope, bool isdefault, cons
     reportError(alloc, Severity::style, "noCopyConstructor", noMemberErrorMessage(scope, "copy constructor", isdefault), CWE398, inconclusive);
 }
 
-void CheckClass::noOperatorEqError(const Scope *scope, bool isdefault, const Token *alloc)
+void CheckClass::noOperatorEqError(const Scope *scope, bool isdefault, const Token *alloc, bool inconclusive)
 {
-    reportError(alloc, Severity::style, "noOperatorEq", noMemberErrorMessage(scope, "operator=", isdefault), CWE398, false);
+    reportError(alloc, Severity::style, "noOperatorEq", noMemberErrorMessage(scope, "operator=", isdefault), CWE398, inconclusive);
 }
 
 void CheckClass::noDestructorError(const Scope *scope, bool isdefault, const Token *alloc)
diff --git a/lib/checkclass.h b/lib/checkclass.h
index 079bf3896..317e3afd3 100644
--- a/lib/checkclass.h
+++ b/lib/checkclass.h
@@ -169,7 +169,7 @@ private:
     //void copyConstructorMallocError(const Token *cctor, const Token *alloc, const std::string& var_name);
     void copyConstructorShallowCopyError(const Token *tok, const std::string& varname);
     void noCopyConstructorError(const Scope *scope, bool isdefault, const Token *alloc, bool inconclusive);
-    void noOperatorEqError(const Scope *scope, bool isdefault, const Token *alloc);
+    void noOperatorEqError(const Scope *scope, bool isdefault, const Token *alloc, bool inconclusive);
     void noDestructorError(const Scope *scope, bool isdefault, const Token *alloc);
     void uninitVarError(const Token *tok, bool isprivate, const std::string &classname, const std::string &varname, bool inconclusive);
     void operatorEqVarError(const Token *tok, const std::string &classname, const std::string &varname, bool inconclusive);
@@ -205,7 +205,7 @@ private:
         //c.copyConstructorMallocError(nullptr, 0, "var");
         c.copyConstructorShallowCopyError(nullptr, "var");
         c.noCopyConstructorError(nullptr, false, nullptr, false);
-        c.noOperatorEqError(nullptr, false, nullptr);
+        c.noOperatorEqError(nullptr, false, nullptr, false);
         c.noDestructorError(nullptr, false, nullptr);
         c.uninitVarError(nullptr, false, "classname", "varname", false);
         c.operatorEqVarError(nullptr, "classname", emptyString, false);
diff --git a/test/testclass.cpp b/test/testclass.cpp
index 84e3ca5a3..20ece9261 100644
--- a/test/testclass.cpp
+++ b/test/testclass.cpp
@@ -736,7 +736,7 @@ private:
                              "   ~F();\n"
                              "   F& operator=(const F&f);\n"
                              "};");
-        ASSERT_EQUALS("[test.cpp:5]: (style, inconclusive) Class 'F' does not have a copy constructor which is recommended since it has dynamic memory/resource allocation(s).\n", errout.str());
+        ASSERT_EQUALS("", errout.str());
 
         checkCopyConstructor("class E { E(E&); };\n" // non-copyable
                              "class F : E\n"
@@ -855,6 +855,15 @@ private:
                              "   ~F();\n"
                              "};");
         ASSERT_EQUALS("", errout.str());
+
+        // base class deletes operator=
+        checkCopyConstructor("struct F : NonCopyable {\n"
+                             "   char* c;\n"
+                             "   F() { c = malloc(100); }\n"
+                             "   F(const F &f);\n"
+                             "   ~F();\n"
+                             "};");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void noDestructor() {