diff --git a/lib/templatesimplifier.cpp b/lib/templatesimplifier.cpp
index 5f56695b8..8b77f876a 100644
--- a/lib/templatesimplifier.cpp
+++ b/lib/templatesimplifier.cpp
@@ -600,11 +600,16 @@ void TemplateSimplifier::useDefaultArgumentValues(const std::list<Token *> &temp
                 for (std::size_t i = (templatepar - eq.size()); it != eq.end() && i < usedpar; ++i)
                     ++it;
                 while (it != eq.end()) {
+                    int indentlevel = 0;
                     tok->insertToken(",");
                     tok = tok->next();
                     const Token *from = (*it)->next();
                     std::stack<Token *> links;
-                    while (from && (!links.empty() || (from->str() != "," && from->str() != ">"))) {
+                    while (from && (!links.empty() || (from->str() != "," && (indentlevel || from->str() != ">")))) {
+                        if (from->str() == "<")
+                            ++indentlevel;
+                        else if (from->str() == ">")
+                            --indentlevel;
                         tok->insertToken(from->str(), from->originalName());
                         tok = tok->next();
                         if (Token::Match(tok, "(|["))
diff --git a/test/testsimplifytokens.cpp b/test/testsimplifytokens.cpp
index 27a8d1e0f..b55eae209 100644
--- a/test/testsimplifytokens.cpp
+++ b/test/testsimplifytokens.cpp
@@ -139,6 +139,7 @@ private:
         TEST_CASE(template44);  // #5297 - TemplateSimplifier::simplifyCalculations not eager enough
         TEST_CASE(template45);  // #5814 - syntax error reported for valid code
         TEST_CASE(template46);  // #5816 - syntax error reported for valid code
+        TEST_CASE(template47);  // #6023 - syntax error reported for valid code
         TEST_CASE(template_unhandled);
         TEST_CASE(template_default_parameter);
         TEST_CASE(template_default_type);
@@ -2425,6 +2426,12 @@ private:
         ASSERT_EQUALS("", errout.str());
     }
 
+    void template47() { // #6023
+        tok("template <typename T1, typename T2 = T3<T1> > class C1 {}; "
+            "class C2 : public C1<C2> {};");
+        ASSERT_EQUALS("", errout.str());
+    }
+
     void template_default_parameter() {
         {
             const char code[] = "template <class T, int n=3>\n"