diff --git a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/contentassist/ParameterGuesser.java b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/contentassist/ParameterGuesser.java
index 0a844ada7ca..4f579d87f59 100644
--- a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/contentassist/ParameterGuesser.java
+++ b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/contentassist/ParameterGuesser.java
@@ -145,7 +145,7 @@ public class ParameterGuesser {
 			throws CModelException {
 		IType elementType = getType(element);
 		String elementName = element.getName();
-		if (elementType != null
+		if (elementType != null && enclosingType != null
 				&& (elementType.toString().equals(enclosingType.toString())
 						|| elementType.isSameType(enclosingType)
 						|| isImplicitlyConvertible(enclosingType, elementType, ast)