diff --git a/lsp/org.eclipse.cdt.lsp.core/src/org/eclipse/cdt/lsp/internal/text/ResolveDocumentUri.java b/lsp/org.eclipse.cdt.lsp.core/src/org/eclipse/cdt/lsp/internal/text/ResolveDocumentUri.java
index 9f1f72aa9bd..82cc60f18c2 100644
--- a/lsp/org.eclipse.cdt.lsp.core/src/org/eclipse/cdt/lsp/internal/text/ResolveDocumentUri.java
+++ b/lsp/org.eclipse.cdt.lsp.core/src/org/eclipse/cdt/lsp/internal/text/ResolveDocumentUri.java
@@ -21,7 +21,7 @@ import org.eclipse.jface.text.IDocument;
 import org.eclipse.lsp4e.LSPEclipseUtils;
 
 @SuppressWarnings("restriction")
-public class ResolveDocumentUri implements Function<IDocument, Optional<URI>> {
+public final class ResolveDocumentUri implements Function<IDocument, Optional<URI>> {
 
 	@Override
 	public Optional<URI> apply(IDocument document) {