diff --git a/com.ibm.wala.cast/.settings/org.eclipse.jdt.core.prefs b/com.ibm.wala.cast/.settings/org.eclipse.jdt.core.prefs
index bbaf02e5c..f859676e9 100644
--- a/com.ibm.wala.cast/.settings/org.eclipse.jdt.core.prefs
+++ b/com.ibm.wala.cast/.settings/org.eclipse.jdt.core.prefs
@@ -29,7 +29,7 @@ org.eclipse.jdt.core.compiler.problem.deprecationWhenOverridingDeprecatedMethod=
 org.eclipse.jdt.core.compiler.problem.discouragedReference=error
 org.eclipse.jdt.core.compiler.problem.emptyStatement=warning
 org.eclipse.jdt.core.compiler.problem.enumIdentifier=error
-org.eclipse.jdt.core.compiler.problem.explicitlyClosedAutoCloseable=warning
+org.eclipse.jdt.core.compiler.problem.explicitlyClosedAutoCloseable=error
 org.eclipse.jdt.core.compiler.problem.fallthroughCase=error
 org.eclipse.jdt.core.compiler.problem.fatalOptionalError=disabled
 org.eclipse.jdt.core.compiler.problem.fieldHiding=ignore