diff --git a/nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-framework-core/src/main/java/org/apache/nifi/controller/repository/StandardProcessSession.java b/nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-framework-core/src/main/java/org/apache/nifi/controller/repository/StandardProcessSession.java
index bf9b174591..c6e79bfaf3 100644
--- a/nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-framework-core/src/main/java/org/apache/nifi/controller/repository/StandardProcessSession.java
+++ b/nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-framework-core/src/main/java/org/apache/nifi/controller/repository/StandardProcessSession.java
@@ -2677,7 +2677,7 @@ public final class StandardProcessSession implements ProcessSession, ProvenanceE
             if (outStream == null) {
                 claimCache.flush(oldClaim);
 
-                try (final InputStream oldClaimIn = context.getContentRepository().read(oldClaim)) {
+                try (final InputStream oldClaimIn = read(source)) {
                     newClaim = context.getContentRepository().create(context.getConnectable().isLossTolerant());
                     claimLog.debug("Creating ContentClaim {} for 'append' for {}", newClaim, source);
 
diff --git a/nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-framework-core/src/test/java/org/apache/nifi/controller/repository/TestStandardProcessSession.java b/nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-framework-core/src/test/java/org/apache/nifi/controller/repository/TestStandardProcessSession.java
index 53019b2957..f6089dc045 100644
--- a/nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-framework-core/src/test/java/org/apache/nifi/controller/repository/TestStandardProcessSession.java
+++ b/nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-framework-core/src/test/java/org/apache/nifi/controller/repository/TestStandardProcessSession.java
@@ -38,6 +38,7 @@ import java.io.FilterOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
@@ -73,6 +74,7 @@ import org.apache.nifi.flowfile.attributes.CoreAttributes;
 import org.apache.nifi.groups.ProcessGroup;
 import org.apache.nifi.processor.FlowFileFilter;
 import org.apache.nifi.processor.FlowFileFilter.FlowFileFilterResult;
+import org.apache.nifi.processor.ProcessSession;
 import org.apache.nifi.processor.Relationship;
 import org.apache.nifi.processor.exception.FlowFileAccessException;
 import org.apache.nifi.processor.exception.MissingFlowFileException;
@@ -1176,6 +1178,36 @@ public class TestStandardProcessSession {
         assertEquals("Hello, World", new String(buff));
     }
 
+    @Test
+    public void testAppendToFlowFileWhereResourceClaimHasMultipleContentClaims() throws IOException {
+        final Relationship relationship = new Relationship.Builder().name("A").build();
+
+        FlowFile ffa = session.create();
+        ffa = session.write(ffa, (out) -> out.write('A'));
+        session.transfer(ffa, relationship);
+
+        FlowFile ffb = session.create();
+        ffb = session.write(ffb, (out) -> out.write('B'));
+        session.transfer(ffb, relationship);
+        session.commit();
+
+        final ProcessSession newSession = new StandardProcessSession(context, () -> false);
+        FlowFile toUpdate = newSession.get();
+        newSession.append(toUpdate, out -> out.write('C'));
+
+        // Read the content back and ensure that it is correct
+        final byte[] buff;
+        try (final ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
+            newSession.read(toUpdate, in -> StreamUtils.copy(in, baos));
+            buff = baos.toByteArray();
+        }
+
+        final String output = new String(buff, StandardCharsets.UTF_8);
+        assertEquals("AC", output);
+        newSession.transfer(toUpdate);
+        newSession.commit();
+    }
+
     @Test
     public void testAppendDoesNotDecrementContentClaimIfNotNeeded() {
         FlowFile flowFile = session.create();