diff --git a/com.avaloq.tools.ddk.xtext.ui.test/src/com/avaloq/tools/ddk/xtext/ui/editor/findrefs/FastReferenceSearchResultContentProviderTest.java b/com.avaloq.tools.ddk.xtext.ui.test/src/com/avaloq/tools/ddk/xtext/ui/editor/findrefs/FastReferenceSearchResultContentProviderTest.java
new file mode 100644
index 0000000000..ed00e67b97
--- /dev/null
+++ b/com.avaloq.tools.ddk.xtext.ui.test/src/com/avaloq/tools/ddk/xtext/ui/editor/findrefs/FastReferenceSearchResultContentProviderTest.java
@@ -0,0 +1,67 @@
+/*******************************************************************************
+ * Copyright (c) 2026 Avaloq Group AG and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Avaloq Group AG - initial API and implementation
+ *******************************************************************************/
+package com.avaloq.tools.ddk.xtext.ui.editor.findrefs;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.eclipse.emf.common.util.URI;
+import org.eclipse.jface.viewers.TreeViewer;
+import org.eclipse.xtext.resource.IReferenceDescription;
+import org.eclipse.xtext.resource.IResourceDescription;
+import org.eclipse.xtext.resource.IResourceDescriptions;
+import org.eclipse.xtext.ui.editor.findrefs.ReferenceSearchResult;
+import org.junit.jupiter.api.Test;
+
+
+/**
+ * Tests for {@link FastReferenceSearchResultContentProvider}.
+ */
+@SuppressWarnings("nls")
+public class FastReferenceSearchResultContentProviderTest {
+
+  private static final URI FIRST_SOURCE = URI.createURI("platform:/resource/project/a.test#/0");
+  private static final URI SECOND_SOURCE = URI.createURI("platform:/resource/project/b.test#/0");
+  @Test
+  public void inputChangedToleratesReferencesAcceptedWhileRepopulating() {
+    List<IReferenceDescription> matchingReferences = new ArrayList<>();
+    matchingReferences.add(reference(FIRST_SOURCE));
+    ReferenceSearchResult searchResult = mock(ReferenceSearchResult.class);
+    when(searchResult.getMatchingReferences()).thenReturn(matchingReferences);
+
+    // the search thread accepts another reference while the UI thread is repopulating from the live list
+    IResourceDescription resourceDescription = mock(IResourceDescription.class);
+    when(resourceDescription.getURI()).thenReturn(FIRST_SOURCE.trimFragment());
+    IResourceDescriptions resourceDescriptions = mock(IResourceDescriptions.class);
+    when(resourceDescriptions.getResourceDescription(any())).thenAnswer(invocation -> {
+      if (matchingReferences.size() == 1) {
+        matchingReferences.add(reference(SECOND_SOURCE));
+      }
+      return resourceDescription;
+    });
+
+    FastReferenceSearchResultContentProvider provider = new FastReferenceSearchResultContentProvider(resourceDescriptions);
+    TreeViewer viewer = mock(TreeViewer.class);
+    assertDoesNotThrow(() -> provider.inputChanged(viewer, null, searchResult));
+  }
+
+  private static IReferenceDescription reference(final URI sourceEObjectUri) {
+    IReferenceDescription reference = mock(IReferenceDescription.class);
+    when(reference.getSourceEObjectUri()).thenReturn(sourceEObjectUri);
+    return reference;
+  }
+
+}
diff --git a/com.avaloq.tools.ddk.xtext.ui.test/src/com/avaloq/tools/ddk/xtext/ui/test/XtextUiTestSuite.java b/com.avaloq.tools.ddk.xtext.ui.test/src/com/avaloq/tools/ddk/xtext/ui/test/XtextUiTestSuite.java
index 7a3be78266..2eaf9266eb 100644
--- a/com.avaloq.tools.ddk.xtext.ui.test/src/com/avaloq/tools/ddk/xtext/ui/test/XtextUiTestSuite.java
+++ b/com.avaloq.tools.ddk.xtext.ui.test/src/com/avaloq/tools/ddk/xtext/ui/test/XtextUiTestSuite.java
@@ -14,6 +14,7 @@
 import org.junit.platform.suite.api.SelectClasses;
 import org.junit.platform.suite.api.Suite;
 
+import com.avaloq.tools.ddk.xtext.ui.editor.findrefs.FastReferenceSearchResultContentProviderTest;
 import com.avaloq.tools.ddk.xtext.ui.quickfix.WorkbenchResolutionAdaptorRunTest;
 import com.avaloq.tools.ddk.xtext.ui.quickfix.WorkbenchResolutionAdaptorTest;
 import com.avaloq.tools.ddk.xtext.ui.templates.ResourceNameTemplateVariableResolverTest;
@@ -31,7 +32,8 @@
   WorkbenchResolutionAdaptorTest.class,
   TemplateProposalProviderHelperTest.class,
   ResourceNameTemplateVariableResolverTest.class,
-  SimpleEnumTemplateVariableResolverTest.class
+  SimpleEnumTemplateVariableResolverTest.class,
+  FastReferenceSearchResultContentProviderTest.class
   // @Format-On
 })
 public class XtextUiTestSuite {
diff --git a/com.avaloq.tools.ddk.xtext.ui/META-INF/MANIFEST.MF b/com.avaloq.tools.ddk.xtext.ui/META-INF/MANIFEST.MF
index 609ac52451..79e450c5d7 100644
--- a/com.avaloq.tools.ddk.xtext.ui/META-INF/MANIFEST.MF
+++ b/com.avaloq.tools.ddk.xtext.ui/META-INF/MANIFEST.MF
@@ -2,7 +2,7 @@ Manifest-Version: 1.0
 Bundle-ManifestVersion: 2
 Bundle-Name: com.avaloq.tools.ddk.xtext.ui
 Bundle-SymbolicName: com.avaloq.tools.ddk.xtext.ui;singleton:=true
-Bundle-Version: 17.3.3.qualifier
+Bundle-Version: 17.3.4.qualifier
 Bundle-Vendor: Avaloq Group AG
 Bundle-RequiredExecutionEnvironment: JavaSE-21
 Bundle-ActivationPolicy: lazy
diff --git a/com.avaloq.tools.ddk.xtext.ui/pom.xml b/com.avaloq.tools.ddk.xtext.ui/pom.xml
index c0672c7749..46bec80919 100644
--- a/com.avaloq.tools.ddk.xtext.ui/pom.xml
+++ b/com.avaloq.tools.ddk.xtext.ui/pom.xml
@@ -6,7 +6,7 @@
     <version>18.0.1-SNAPSHOT</version>
     <relativePath>../ddk-parent</relativePath>
   </parent>
-  <version>17.3.3-SNAPSHOT</version>
+  <version>17.3.4-SNAPSHOT</version>
   <groupId>com.avaloq.tools.ddk</groupId>
   <artifactId>com.avaloq.tools.ddk.xtext.ui</artifactId>
   <packaging>eclipse-plugin</packaging>
diff --git a/com.avaloq.tools.ddk.xtext.ui/src/com/avaloq/tools/ddk/xtext/ui/editor/findrefs/FastReferenceSearchResultContentProvider.java b/com.avaloq.tools.ddk.xtext.ui/src/com/avaloq/tools/ddk/xtext/ui/editor/findrefs/FastReferenceSearchResultContentProvider.java
index 657f032922..bb6c7ba4ae 100644
--- a/com.avaloq.tools.ddk.xtext.ui/src/com/avaloq/tools/ddk/xtext/ui/editor/findrefs/FastReferenceSearchResultContentProvider.java
+++ b/com.avaloq.tools.ddk.xtext.ui/src/com/avaloq/tools/ddk/xtext/ui/editor/findrefs/FastReferenceSearchResultContentProvider.java
@@ -115,8 +115,11 @@ public void inputChanged(final Viewer v, final Object oldInput, final Object new
       if (newInput instanceof ReferenceSearchResult && v instanceof TreeViewer) {
         ((ReferenceSearchResult) newInput).addListener(this);
         this.viewer = (TreeViewer) v;
-        for (IReferenceDescription referenceDescription : ((ReferenceSearchResult) newInput).getMatchingReferences()) {
-          addReference(referenceDescription);
+        // iterate a copy: the search job may still be appending to the live list
+        for (IReferenceDescription referenceDescription : Lists.newArrayList(((ReferenceSearchResult) newInput).getMatchingReferences())) {
+          if (referenceDescription != null) {
+            addReference(referenceDescription);
+          }
         }
       }
     }