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 ba0378e9f23..f7801bafed8 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
@@ -1278,6 +1278,16 @@ public class CPPTemplates {
 				if (r < 0)
 					return r;
 			}
+		} else if (binding instanceof ICPPDeferredVariableInstance dvi) {
+			if (dvi.getTemplateDefinition() instanceof ICPPTemplateTemplateParameter) {
+				r = combinePackSize(r, determinePackSize((ICPPUnknownBinding) dvi.getTemplateDefinition(), tpMap));
+			}
+			ICPPTemplateArgument[] args = dvi.getTemplateArguments();
+			for (ICPPTemplateArgument arg : args) {
+				r = combinePackSize(r, determinePackSize(arg, tpMap));
+				if (r < 0)
+					return r;
+			}
 		}
 		IBinding ownerBinding = binding.getOwner();
 		if (ownerBinding instanceof IType)