diff --git a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2TemplateTests.java b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2TemplateTests.java
index b9022b5b30c..a84453cf7c1 100644
--- a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2TemplateTests.java
+++ b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2TemplateTests.java
@@ -8041,6 +8041,34 @@ public class AST2TemplateTests extends AST2TestBase {
 		IVariable answer = helper.assertNonProblem("answer");
 		assertVariableValue(answer, 1);
 	}
+	
+
+	//	template <template <class> class ... Mixins>
+	//	struct C : Mixins<int>... {};
+	//	  
+	//	template <typename>
+	//	struct SpecificMixin {};
+	//	
+	//	constexpr bool answer = __is_base_of(SpecificMixin<int>, C<SpecificMixin>);
+	public void testTemplateTemplateParameterPack_487703a() throws Exception {
+		BindingAssertionHelper helper = getAssertionHelper();
+		IVariable answer = helper.assertNonProblem("answer");
+		assertVariableValue(answer, 1);
+	}
+	
+	//  template <template <class> class ... Mixins>
+	//  struct C : Mixins<C<Mixins...>>... {};
+	//
+	//  template <typename>
+	//  struct SpecificMixin {};
+	//
+	//  typedef C<SpecificMixin> Waldo;
+	//  constexpr bool answer = __is_base_of(SpecificMixin<Waldo>, Waldo);
+	public void testTemplateTemplateParameterPack_487703b() throws Exception {
+		BindingAssertionHelper helper = getAssertionHelper();
+		IVariable answer = helper.assertNonProblem("answer");
+		assertVariableValue(answer, 1);
+	}
 
 	// struct S {
 	//     void kind();
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPTemplates.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPTemplates.java
index 32673583a67..4dfb55de6b1 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPTemplates.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPTemplates.java
@@ -1202,6 +1202,10 @@ public class CPPTemplates {
 		int r= PACK_SIZE_NOT_FOUND;
 		if (binding instanceof ICPPDeferredClassInstance) {
 			ICPPDeferredClassInstance dcl= (ICPPDeferredClassInstance) binding;
+			if (dcl.getClassTemplate() instanceof ICPPTemplateTemplateParameter) {
+				r = combinePackSize(r, determinePackSize((ICPPTemplateParameter) dcl.getClassTemplate(), 
+						tpMap));
+			}
 			ICPPTemplateArgument[] args = dcl.getTemplateArguments();
 			for (ICPPTemplateArgument arg : args) {
 				r= combinePackSize(r, determinePackSize(arg, tpMap));