diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/LookupData.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/LookupData.java
index 8b7ebf0ad01..9eb2445c486 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/LookupData.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/LookupData.java
@@ -519,6 +519,7 @@ public class LookupData extends ScopeLookupData {
 	public void setFunctionArguments(boolean containsImpliedObject, ICPPEvaluation... exprs) {
 		argsContainImpliedObject= containsImpliedObject;
 		functionArgs= exprs;
+		functionArgTypes = null;
 	}
 
 	public void setFunctionArguments(boolean containsImpliedObject, IASTInitializerClause... exprs) {