diff --git a/chemclipse/plugins/org.eclipse.chemclipse.xxd.process.supplier.pca.ui/.settings/org.eclipse.jdt.core.prefs b/chemclipse/plugins/org.eclipse.chemclipse.xxd.process.supplier.pca.ui/.settings/org.eclipse.jdt.core.prefs
index 8fc170eb86..a5d3e6e205 100644
--- a/chemclipse/plugins/org.eclipse.chemclipse.xxd.process.supplier.pca.ui/.settings/org.eclipse.jdt.core.prefs
+++ b/chemclipse/plugins/org.eclipse.chemclipse.xxd.process.supplier.pca.ui/.settings/org.eclipse.jdt.core.prefs
@@ -5,7 +5,7 @@ org.eclipse.jdt.core.compiler.compliance=21
 org.eclipse.jdt.core.compiler.problem.assertIdentifier=error
 org.eclipse.jdt.core.compiler.problem.enablePreviewFeatures=disabled
 org.eclipse.jdt.core.compiler.problem.enumIdentifier=error
-org.eclipse.jdt.core.compiler.problem.forbiddenReference=info
+org.eclipse.jdt.core.compiler.problem.forbiddenReference=error
 org.eclipse.jdt.core.compiler.problem.reportPreviewFeatures=warning
 org.eclipse.jdt.core.compiler.release=enabled
 org.eclipse.jdt.core.compiler.source=21
diff --git a/chemclipse/plugins/org.eclipse.chemclipse.xxd.process.supplier.pca/.settings/org.eclipse.jdt.core.prefs b/chemclipse/plugins/org.eclipse.chemclipse.xxd.process.supplier.pca/.settings/org.eclipse.jdt.core.prefs
index 01bc25fa0d..56d5831533 100644
--- a/chemclipse/plugins/org.eclipse.chemclipse.xxd.process.supplier.pca/.settings/org.eclipse.jdt.core.prefs
+++ b/chemclipse/plugins/org.eclipse.chemclipse.xxd.process.supplier.pca/.settings/org.eclipse.jdt.core.prefs
@@ -4,5 +4,5 @@ org.eclipse.jdt.core.compiler.codegen.targetPlatform=21
 org.eclipse.jdt.core.compiler.compliance=21
 org.eclipse.jdt.core.compiler.problem.assertIdentifier=error
 org.eclipse.jdt.core.compiler.problem.enumIdentifier=error
+org.eclipse.jdt.core.compiler.problem.forbiddenReference=error
 org.eclipse.jdt.core.compiler.source=21
-org.eclipse.jdt.core.compiler.problem.forbiddenReference=info