diff --git a/lib/checkclass.cpp b/lib/checkclass.cpp
index 408031840..fafc78aa1 100644
--- a/lib/checkclass.cpp
+++ b/lib/checkclass.cpp
@@ -898,7 +898,7 @@ static const Scope* findFunctionOf(const Scope* scope)
     return 0;
 }
 
-void CheckClass::noMemset()
+void CheckClass::checkMemset()
 {
     const std::size_t functions = symbolDatabase->functionScopes.size();
     for (std::size_t i = 0; i < functions; ++i) {
@@ -949,6 +949,20 @@ void CheckClass::noMemset()
 
                         if (derefs == 0)
                             type = var->typeScope();
+
+                        // TODO: The SymbolDatabase mix up variables in nested structs.
+                        //       So we must bailout right now if there are nested structs.
+                        bool bailout = false;
+                        for (const Token *typetok2 = var->typeStartToken(); typetok2 && typetok2 != var->typeEndToken(); typetok2 = typetok2->next()) {
+                            if (typetok2->str() == "::")
+                                bailout = true;
+                            if (typetok2->str() == "{") {
+                                bailout = false;
+                                break;
+                            }
+                        }
+                        if (bailout)
+                            continue;
                     }
                 }
 
diff --git a/lib/checkclass.h b/lib/checkclass.h
index e455b21e1..6cff648a3 100644
--- a/lib/checkclass.h
+++ b/lib/checkclass.h
@@ -50,7 +50,7 @@ public:
         CheckClass checkClass(tokenizer, settings, errorLogger);
 
         // can't be a simplified check .. the 'sizeof' is used.
-        checkClass.noMemset();
+        checkClass.checkMemset();
     }
 
     /** @brief Run checks on the simplified token list */
@@ -93,7 +93,7 @@ public:
      * It can also overwrite the virtual table.
      * Important: The checking doesn't work on simplified tokens list.
      */
-    void noMemset();
+    void checkMemset();
     void checkMemsetType(const Scope *start, const Token *tok, const Scope *type, bool allocation);
 
     /** @brief 'operator=' should return something and it should not be const. */
diff --git a/test/testclass.cpp b/test/testclass.cpp
index 206a140fe..9a80b9f61 100644
--- a/test/testclass.cpp
+++ b/test/testclass.cpp
@@ -2042,7 +2042,7 @@ private:
 
         // Check..
         CheckClass checkClass(&tokenizer, &settings, this);
-        checkClass.noMemset();
+        checkClass.checkMemset();
     }
 
     void memsetOnClass() {
@@ -2219,7 +2219,7 @@ private:
                       "    n1::Fred fred;\n"
                       "    memset(&fred, 0, sizeof(fred));\n"
                       "}");
-        ASSERT_EQUALS("[test.cpp:10]: (error) Using 'memset' on class that contains a 'std::string'.\n", errout.str());
+        TODO_ASSERT_EQUALS("[test.cpp:10]: (error) Using 'memset' on class that contains a 'std::string'.\n", "", errout.str());
 
         checkNoMemset("class A {\n"
                       "  virtual ~A() { }\n"
@@ -2231,6 +2231,15 @@ private:
                       "  memset(arr, 0, N * sizeof(A*));\n"
                       "}");
         ASSERT_EQUALS("", errout.str());
+
+        checkNoMemset("class A {\n" // #5116 - nested class data is mixed in the SymbolDatabase
+                      "  std::string s;\n"
+                      "  struct B { int x; };\n"
+                      "};\n"
+                      "void f(A::B *b) {\n"
+                      "  memset(b,0,4);\n"
+                      "}");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void memsetOnStruct() {