diff --git a/headless-services/commons/commons-yaml/src/main/java/org/springframework/ide/vscode/commons/yaml/reconcile/YamlReconcileEngine.java b/headless-services/commons/commons-yaml/src/main/java/org/springframework/ide/vscode/commons/yaml/reconcile/YamlReconcileEngine.java
index 6c123930d..3af04a449 100644
--- a/headless-services/commons/commons-yaml/src/main/java/org/springframework/ide/vscode/commons/yaml/reconcile/YamlReconcileEngine.java
+++ b/headless-services/commons/commons-yaml/src/main/java/org/springframework/ide/vscode/commons/yaml/reconcile/YamlReconcileEngine.java
@@ -19,7 +19,9 @@ import org.springframework.ide.vscode.commons.languageserver.reconcile.Reconcile
 import org.springframework.ide.vscode.commons.util.text.IDocument;
 import org.springframework.ide.vscode.commons.yaml.ast.YamlASTProvider;
 import org.springframework.ide.vscode.commons.yaml.ast.YamlFileAST;
+import org.yaml.snakeyaml.composer.ComposerException;
 import org.yaml.snakeyaml.error.Mark;
+import org.yaml.snakeyaml.error.MarkedYAMLException;
 import org.yaml.snakeyaml.parser.ParserException;
 import org.yaml.snakeyaml.scanner.ScannerException;
 
@@ -45,11 +47,7 @@ public abstract class YamlReconcileEngine implements IReconcileEngine {
 			if (reconciler!=null) {
 				reconciler.reconcile(ast);
 			}
-		} catch (ParserException e) {
-			String msg = e.getProblem();
-			Mark mark = e.getProblemMark();
-			problemCollector.accept(syntaxError(msg, mark.getIndex(), 1));
-		} catch (ScannerException e) {
+		} catch (MarkedYAMLException e) {
 			String msg = e.getProblem();
 			Mark mark = e.getProblemMark();
 			problemCollector.accept(syntaxError(msg, mark.getIndex(), 1));
diff --git a/headless-services/concourse-language-server/src/test/java/org/springframework/ide/vscode/concourse/ConcourseEditorTest.java b/headless-services/concourse-language-server/src/test/java/org/springframework/ide/vscode/concourse/ConcourseEditorTest.java
index 04ddb3749..87bd528c7 100644
--- a/headless-services/concourse-language-server/src/test/java/org/springframework/ide/vscode/concourse/ConcourseEditorTest.java
+++ b/headless-services/concourse-language-server/src/test/java/org/springframework/ide/vscode/concourse/ConcourseEditorTest.java
@@ -4928,6 +4928,22 @@ public class ConcourseEditorTest {
 		);
 	}
 
+	@Test
+	public void referenceToMissingAnchor() throws Exception {
+		Editor editor = harness.newEditor(
+				"repo-dflts: &repo-dflts\n" +
+				"  bogus: bar\n" +
+				"resources:\n" +
+				"- name: foo\n" +
+				"  type: git\n" +
+				"  source:\n" +
+				"    <<: *TYPO\n"
+		);
+		editor.assertProblems(
+				"*|undefined alias TYPO"
+		);
+	}
+
 	@Test
 	public void anchorsAndReferenceSample_1() throws Exception {
 		Editor editor = harness.newEditor(