diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/dom/ast/IType.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/dom/ast/IType.java
index 9e128fac2f3..2d6bb8a35fd 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/dom/ast/IType.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/dom/ast/IType.java
@@ -36,6 +36,7 @@ public interface IType extends Cloneable {
 	 * See {@link ICPPTemplateTemplateParameter#isSameType(IType)} or
 	 * {@link ICPPTemplateTypeParameter#isSameType(IType)} for the semantics of comparing template
 	 * parameters denoting types.
+	 * @param type can be {@code null}.
 	 */
 	public boolean isSameType(IType type);
 }
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPClosureType.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPClosureType.java
index 4a17ae5873c..8d06fab4859 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPClosureType.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPClosureType.java
@@ -325,6 +325,8 @@ public class CPPClosureType extends PlatformObject implements ICPPClassType, ICP
 
 	@Override
 	public boolean isSameType(IType type) {
+		if (type == null)
+			return false;
 		if (type == this)
 			return true;
 		if (type instanceof ITypedef || type instanceof IIndexBinding)