diff --git a/lib/symboldatabase.cpp b/lib/symboldatabase.cpp
index 1e01525db..1fbc22135 100644
--- a/lib/symboldatabase.cpp
+++ b/lib/symboldatabase.cpp
@@ -3056,7 +3056,9 @@ const Token *Type::initBaseInfo(const Token *tok, const Token *tok1)
                 }
             }
 
-            base.type = classScope->check->findType(base.nameTok, classScope);
+            const Type * baseType = classScope->check->findType(base.nameTok, enclosingScope);
+            if (baseType && !baseType->findDependency(this))
+                base.type = baseType;
 
             // save pattern for base class name
             derivedFrom.push_back(base);
diff --git a/lib/tokenize.cpp b/lib/tokenize.cpp
index 0780fd65a..0e7131ae1 100644
--- a/lib/tokenize.cpp
+++ b/lib/tokenize.cpp
@@ -1755,6 +1755,8 @@ namespace {
             fullName = name;
             ScopeInfo3 *scope = parent;
             while (scope && scope->parent) {
+                if (scope->name.empty())
+                    break;
                 fullName = scope->name + " :: " + fullName;
                 scope = scope->parent;
             }
@@ -1770,14 +1772,14 @@ namespace {
         std::set<std::string> recordTypes;
         std::set<std::string> baseTypes;
 
-        ScopeInfo3 *addChild(Type type, const std::string &name, const Token *bodyStart, const Token *bodyEnd) {
-            children.emplace_back(this, type, name, bodyStart, bodyEnd);
+        ScopeInfo3 *addChild(Type scopeType, const std::string &scopeName, const Token *bodyStartToken, const Token *bodyEndToken) {
+            children.emplace_back(this, scopeType, scopeName, bodyStartToken, bodyEndToken);
             return &children.back();
         }
 
-        bool hasChild(const std::string &name) const {
+        bool hasChild(const std::string &childName) const {
             for (const auto & child : children) {
-                if (child.name == name)
+                if (child.name == childName)
                     return true;
             }
             return false;
@@ -1824,24 +1826,39 @@ namespace {
             return nullptr;
         }
 
+        const ScopeInfo3 * findInChildren(const std::string & scope) const {
+            for (const auto & child : children) {
+                if (child.name == scope || child.fullName == scope)
+                    return &child;
+                else {
+                    const ScopeInfo3 * temp = child.findInChildren(scope);
+                    if (temp)
+                        return temp;
+                }
+            }
+            return nullptr;
+        }
+
         const ScopeInfo3 * findScope(const std::string & scope) const {
             const ScopeInfo3 * tempScope = this;
             while (tempScope) {
+                // check children
                 for (const auto & child : tempScope->children) {
-                    if (child.type == Record && (child.name == scope || child.fullName == scope))
+                    if (&child != this && child.type == Record && (child.name == scope || child.fullName == scope))
                         return &child;
                 }
+                // check siblings for same name
+                if (tempScope->parent) {
+                    for (const auto &sibling : tempScope->parent->children) {
+                        if (sibling.name == tempScope->name && &sibling != this) {
+                            const ScopeInfo3 * temp = sibling.findInChildren(scope);
+                            if (temp)
+                                return temp;
+                        }
+                    }
+                }
                 tempScope = tempScope->parent;
             }
-            // check for another scope with same name
-            const ScopeInfo3 * global = this;
-            while (global->parent)
-                global = global->parent;
-            for (const ScopeInfo3 & tempChild : global->children) {
-                const ScopeInfo3 * temp = tempChild.findScopeRecursive(scope);
-                if (temp)
-                    return temp;
-            }
             return nullptr;
         }
 
diff --git a/test/testclass.cpp b/test/testclass.cpp
index 990fd82fb..29ea8a45f 100644
--- a/test/testclass.cpp
+++ b/test/testclass.cpp
@@ -5546,20 +5546,20 @@ private:
     }
 
     void const61() { // ticket #5606 - don't crash
+        // this code is invalid so a false negative is OK
         checkConst("class MixerParticipant : public MixerParticipant {\n"
                    "    int GetAudioFrame();\n"
                    "};\n"
                    "int MixerParticipant::GetAudioFrame() {\n"
                    "    return 0;\n"
                    "}");
-        ASSERT_EQUALS("[test.cpp:4] -> [test.cpp:2]: (performance, inconclusive) Technically the member function 'MixerParticipant::GetAudioFrame' can be static (but you may consider moving to unnamed namespace).\n", errout.str());
 
+        // this code is invalid so a false negative is OK
         checkConst("class MixerParticipant : public MixerParticipant {\n"
                    "    bool InitializeFileReader() {\n"
                    "       printf(\"music\");\n"
                    "    }\n"
                    "};");
-        ASSERT_EQUALS("[test.cpp:2]: (performance, inconclusive) Technically the member function 'MixerParticipant::InitializeFileReader' can be static (but you may consider moving to unnamed namespace).\n", errout.str());
 
         // Based on an example from SVN source code causing an endless recursion within CheckClass::isConstMemberFunc()
         // A more complete example including a template declaration like
diff --git a/test/testsimplifyusing.cpp b/test/testsimplifyusing.cpp
index 0b3ec5275..0bac2a8ed 100644
--- a/test/testsimplifyusing.cpp
+++ b/test/testsimplifyusing.cpp
@@ -65,6 +65,7 @@ private:
         TEST_CASE(simplifyUsing16);
         TEST_CASE(simplifyUsing17);
         TEST_CASE(simplifyUsing18);
+        TEST_CASE(simplifyUsing19);
 
         TEST_CASE(simplifyUsing8970);
         TEST_CASE(simplifyUsing8971);
@@ -463,6 +464,18 @@ private:
         tok(code, false); // don't crash
     }
 
+    void simplifyUsing19() {
+        const char code[] = "namespace a {\n"
+                            "using b = int;\n"
+                            "void foo::c() { }\n"
+                            "void foo::d() { }\n"
+                            "void foo::e() {\n"
+                            "   using b = float;\n"
+                            "}\n"
+                            "}";
+        tok(code, false); // don't hang
+    }
+
     void simplifyUsing8970() {
         const char code[] = "using V = std::vector<int>;\n"
                             "struct A {\n"