diff --git a/extensions/wikidata/src/org/openrefine/wikidata/editing/EditBatchProcessor.java b/extensions/wikidata/src/org/openrefine/wikidata/editing/EditBatchProcessor.java
index 5c8e98ef7..ab01dff17 100644
--- a/extensions/wikidata/src/org/openrefine/wikidata/editing/EditBatchProcessor.java
+++ b/extensions/wikidata/src/org/openrefine/wikidata/editing/EditBatchProcessor.java
@@ -31,6 +31,7 @@ import java.util.Map;
 import java.util.stream.Collectors;
 
 import org.openrefine.wikidata.schema.entityvalues.ReconEntityIdValue;
+import org.openrefine.wikidata.schema.exceptions.NewItemNotCreatedYetException;
 import org.openrefine.wikidata.updates.ItemUpdate;
 import org.openrefine.wikidata.updates.scheduler.WikibaseAPIUpdateScheduler;
 import org.slf4j.Logger;
@@ -128,7 +129,12 @@ public class EditBatchProcessor {
 
         // Rewrite mentions to new items
         ReconEntityRewriter rewriter = new ReconEntityRewriter(library, update.getItemId());
-        update = rewriter.rewrite(update);
+        try {
+        	update = rewriter.rewrite(update);
+        } catch (NewItemNotCreatedYetException e) {
+        	logger.warn("Failed to rewrite update on entity "+update.getItemId()+". Missing entity: "+e.getMissingEntity()+". Skipping update.");
+        	return;
+        }
 
         try {
             // New item
diff --git a/extensions/wikidata/src/org/openrefine/wikidata/editing/ReconEntityRewriter.java b/extensions/wikidata/src/org/openrefine/wikidata/editing/ReconEntityRewriter.java
index 195862ff6..776b8240b 100644
--- a/extensions/wikidata/src/org/openrefine/wikidata/editing/ReconEntityRewriter.java
+++ b/extensions/wikidata/src/org/openrefine/wikidata/editing/ReconEntityRewriter.java
@@ -1,18 +1,18 @@
 /*******************************************************************************
  * MIT License
- * 
+ *
  * Copyright (c) 2018 Antonin Delpeuch
- * 
+ *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- * 
+ *
  * The above copyright notice and this permission notice shall be included in all
  * copies or substantial portions of the Software.
- * 
+ *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -28,10 +28,12 @@ import java.util.Set;
 import java.util.stream.Collectors;
 
 import org.openrefine.wikidata.schema.entityvalues.ReconItemIdValue;
+import org.openrefine.wikidata.schema.exceptions.NewItemNotCreatedYetException;
 import org.openrefine.wikidata.updates.ItemUpdate;
 import org.wikidata.wdtk.datamodel.helpers.Datamodel;
 import org.wikidata.wdtk.datamodel.helpers.DatamodelConverter;
 import org.wikidata.wdtk.datamodel.implementation.DataObjectFactoryImpl;
+import org.wikidata.wdtk.datamodel.interfaces.EntityIdValue;
 import org.wikidata.wdtk.datamodel.interfaces.ItemIdValue;
 import org.wikidata.wdtk.datamodel.interfaces.MonolingualTextValue;
 import org.wikidata.wdtk.datamodel.interfaces.Statement;
@@ -39,67 +41,101 @@ import org.wikidata.wdtk.datamodel.interfaces.Statement;
 /**
  * A class that rewrites an {@link ItemUpdate}, replacing reconciled entity id
  * values by their concrete values after creation of all the new items involved.
- * 
+ *
  * If an item has not been created yet, an {@link IllegalArgumentException} will
  * be raised.
- * 
+ *
  * The subject is treated as a special case: it is returned unchanged. This is
  * because it is guaranteed not to appear in the update (but it does appear in
  * the datamodel representation as the subject is passed around to the Claim
  * objects its document contains).
- * 
+ *
  * @author Antonin Delpeuch
  *
  */
 public class ReconEntityRewriter extends DatamodelConverter {
 
-    private NewItemLibrary library;
-    private ItemIdValue subject;
+	private final NewItemLibrary library;
+	private final ItemIdValue subject;
 
-    /**
-     * Constructor. Sets up a rewriter which uses the provided library to look up
-     * qids of new items, and the subject (which should not be rewritten).
-     * 
-     * @param library
-     * @param subject
-     */
-    public ReconEntityRewriter(NewItemLibrary library, ItemIdValue subject) {
-        super(new DataObjectFactoryImpl());
-        this.library = library;
-        this.subject = subject;
-    }
+	protected static final String notCreatedYetMessage = "Trying to rewrite an update where a new item was not created yet.";
 
-    @Override
-    public ItemIdValue copy(ItemIdValue value) {
-        if (subject.equals(value)) {
-            return value;
-        }
-        if (value instanceof ReconItemIdValue) {
-            ReconItemIdValue recon = (ReconItemIdValue) value;
-            if (recon.isNew()) {
-                String newId = library.getQid(recon.getReconInternalId());
-                if (newId == null) {
-                    throw new IllegalArgumentException(
-                            "Trying to rewrite an update where a new item was not created yet.");
-                }
-                return Datamodel.makeItemIdValue(newId, recon.getRecon().identifierSpace);
-            }
-        }
-        return super.copy(value);
-    }
+	/**
+	 * Constructor. Sets up a rewriter which uses the provided library to look up
+	 * qids of new items.
+	 *
+	 * @param library
+	 *      the collection of items already created
+	 * @param subject
+	 *      the subject id of the entity to rewrite
+	 */
+	public ReconEntityRewriter(NewItemLibrary library, ItemIdValue subject) {
+		super(new DataObjectFactoryImpl());
+		this.library = library;
+		this.subject = subject;
+	}
+
+	@Override
+	public ItemIdValue copy(ItemIdValue value) {
+		if (value instanceof ReconItemIdValue) {
+			ReconItemIdValue recon = (ReconItemIdValue) value;
+			if (recon.isNew()) {
+				String newId = library.getQid(recon.getReconInternalId());
+				if (newId == null) {
+					if (subject.equals(recon)) {
+						return subject;
+					} else {
+						throw new MissingEntityIdFound(recon);
+					}
+				}
+				return Datamodel.makeItemIdValue(newId, recon.getRecon().identifierSpace);
+			}
+		}
+		return super.copy(value);
+	}
+
+	/**
+	 * Rewrite an update, replacing references to all entities already
+	 * created by their fresh identifiers. The subject id might not have been
+	 * created already, in which case it will be left untouched. All the other
+	 * entities need to have been created already.
+	 *
+	 * @param update
+	 *      the update to rewrite
+	 * @return
+	 *      the rewritten update
+	 * @throws NewItemNotCreatedYetException
+	 *      if any non-subject entity had not been created yet
+	 */
+	public ItemUpdate rewrite(ItemUpdate update) throws NewItemNotCreatedYetException {
+		try {
+			ItemIdValue subject = copy(update.getItemId());
+			Set<MonolingualTextValue> labels = update.getLabels().stream().map(l -> copy(l)).collect(Collectors.toSet());
+			Set<MonolingualTextValue> labelsIfNew = update.getLabelsIfNew().stream().map(l -> copy(l)).collect(Collectors.toSet());
+			Set<MonolingualTextValue> descriptions = update.getDescriptions().stream().map(l -> copy(l))
+					.collect(Collectors.toSet());
+			Set<MonolingualTextValue> descriptionsIfNew = update.getDescriptionsIfNew().stream().map(l -> copy(l))
+					.collect(Collectors.toSet());
+			Set<MonolingualTextValue> aliases = update.getAliases().stream().map(l -> copy(l)).collect(Collectors.toSet());
+			List<Statement> addedStatements = update.getAddedStatements().stream().map(l -> copy(l))
+					.collect(Collectors.toList());
+			Set<Statement> deletedStatements = update.getDeletedStatements().stream().map(l -> copy(l))
+					.collect(Collectors.toSet());
+			return new ItemUpdate(subject, addedStatements, deletedStatements, labels, labelsIfNew, descriptions, descriptionsIfNew, aliases);
+		} catch(MissingEntityIdFound e) {
+			throw new NewItemNotCreatedYetException(e.value);
+		}
+	}
+
+	/**
+	 * Unchecked version of {@class NewItemNotCreatedYetException}, for internal use only.
+	 */
+	protected static class MissingEntityIdFound extends Error {
+		private static final long serialVersionUID = 1L;
+		protected EntityIdValue value;
+		public MissingEntityIdFound(EntityIdValue missing) {
+			this.value = missing;
+		}
+	}
 
-    public ItemUpdate rewrite(ItemUpdate update) {
-        Set<MonolingualTextValue> labels = update.getLabels().stream().map(l -> copy(l)).collect(Collectors.toSet());
-        Set<MonolingualTextValue> labelsIfNew = update.getLabelsIfNew().stream().map(l -> copy(l)).collect(Collectors.toSet());
-        Set<MonolingualTextValue> descriptions = update.getDescriptions().stream().map(l -> copy(l))
-                .collect(Collectors.toSet());
-        Set<MonolingualTextValue> descriptionsIfNew = update.getDescriptionsIfNew().stream().map(l -> copy(l))
-                .collect(Collectors.toSet());
-        Set<MonolingualTextValue> aliases = update.getAliases().stream().map(l -> copy(l)).collect(Collectors.toSet());
-        List<Statement> addedStatements = update.getAddedStatements().stream().map(l -> copy(l))
-                .collect(Collectors.toList());
-        Set<Statement> deletedStatements = update.getDeletedStatements().stream().map(l -> copy(l))
-                .collect(Collectors.toSet());
-        return new ItemUpdate(update.getItemId(), addedStatements, deletedStatements, labels, labelsIfNew, descriptions, descriptionsIfNew, aliases);
-    }
 }
diff --git a/extensions/wikidata/src/org/openrefine/wikidata/schema/exceptions/NewItemNotCreatedYetException.java b/extensions/wikidata/src/org/openrefine/wikidata/schema/exceptions/NewItemNotCreatedYetException.java
new file mode 100644
index 000000000..38880be96
--- /dev/null
+++ b/extensions/wikidata/src/org/openrefine/wikidata/schema/exceptions/NewItemNotCreatedYetException.java
@@ -0,0 +1,19 @@
+package org.openrefine.wikidata.schema.exceptions;
+
+import org.wikidata.wdtk.datamodel.interfaces.EntityIdValue;
+
+public class NewItemNotCreatedYetException extends Exception {
+	private static final long serialVersionUID = -563535295696710197L;
+	
+	private final EntityIdValue value;
+
+	public NewItemNotCreatedYetException(EntityIdValue value) {
+		super("Attempted to rewrite an entity which was not created yet: "+value);
+		this.value = value;
+	}
+
+	public EntityIdValue getMissingEntity() {
+		return value;
+	}
+
+}
diff --git a/extensions/wikidata/src/org/openrefine/wikidata/updates/ItemUpdate.java b/extensions/wikidata/src/org/openrefine/wikidata/updates/ItemUpdate.java
index 46def6711..90713d10a 100644
--- a/extensions/wikidata/src/org/openrefine/wikidata/updates/ItemUpdate.java
+++ b/extensions/wikidata/src/org/openrefine/wikidata/updates/ItemUpdate.java
@@ -407,13 +407,21 @@ public class ItemUpdate {
         builder.append("<Update on ");
         builder.append(qid);
         if (!labels.isEmpty()) {
-            builder.append("\n  Labels: ");
+            builder.append("\n  Labels (override): ");
             builder.append(labels);
         }
+        if (!labelsIfNew.isEmpty()) {
+            builder.append("\n  Labels (if new): ");
+            builder.append(labelsIfNew);
+        }
         if (!descriptions.isEmpty()) {
-            builder.append("\n  Descriptions: ");
+            builder.append("\n  Descriptions (override): ");
             builder.append(descriptions);
         }
+        if (!descriptionsIfNew.isEmpty()) {
+            builder.append("\n  Descriptions (if new): ");
+            builder.append(descriptionsIfNew);
+        }
         if (!aliases.isEmpty()) {
             builder.append("\n  Aliases: ");
             builder.append(aliases);
diff --git a/extensions/wikidata/tests/src/org/openrefine/wikidata/editing/ReconEntityRewriterTest.java b/extensions/wikidata/tests/src/org/openrefine/wikidata/editing/ReconEntityRewriterTest.java
index 66c8956eb..2cc84f6fa 100644
--- a/extensions/wikidata/tests/src/org/openrefine/wikidata/editing/ReconEntityRewriterTest.java
+++ b/extensions/wikidata/tests/src/org/openrefine/wikidata/editing/ReconEntityRewriterTest.java
@@ -1,18 +1,18 @@
 /*******************************************************************************
  * MIT License
- * 
+ *
  * Copyright (c) 2018 Antonin Delpeuch
- * 
+ *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- * 
+ *
  * The above copyright notice and this permission notice shall be included in all
  * copies or substantial portions of the Software.
- * 
+ *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -25,6 +25,7 @@ package org.openrefine.wikidata.editing;
 
 import static org.testng.Assert.assertEquals;
 
+import org.openrefine.wikidata.schema.exceptions.NewItemNotCreatedYetException;
 import org.openrefine.wikidata.testing.TestingData;
 import org.openrefine.wikidata.updates.ItemUpdate;
 import org.openrefine.wikidata.updates.ItemUpdateBuilder;
@@ -35,54 +36,103 @@ import org.wikidata.wdtk.datamodel.interfaces.ItemIdValue;
 
 public class ReconEntityRewriterTest {
 
-    NewItemLibrary library = null;
-    ReconEntityRewriter rewriter = null;
-    ItemIdValue subject = TestingData.newIdA;
-    ItemIdValue newlyCreated = Datamodel.makeWikidataItemIdValue("Q1234");
+	NewItemLibrary library = null;
+	ReconEntityRewriter rewriter = null;
+	ItemIdValue newlyCreated = Datamodel.makeWikidataItemIdValue("Q1234");
 
-    @BeforeMethod
-    public void setUp() {
-        library = new NewItemLibrary();
-        rewriter = new ReconEntityRewriter(library, subject);
-    }
+	@BeforeMethod
+	public void setUp() {
+		library = new NewItemLibrary();
+	}
 
-    @Test(expectedExceptions = IllegalArgumentException.class)
-    public void testNotCreatedYet() {
-        rewriter.copy(TestingData.newIdB);
-    }
+	@Test(expectedExceptions = ReconEntityRewriter.MissingEntityIdFound.class)
+	public void testNotCreatedYet() {
+		rewriter = new ReconEntityRewriter(library, TestingData.newIdA);
+		rewriter.copy(TestingData.newIdB);
+	}
 
-    @Test
-    public void testSuccessfulRewrite() {
-        library.setQid(4567L, "Q1234");
-        assertEquals(newlyCreated, rewriter.copy(TestingData.newIdB));
-    }
+	@Test
+	public void testSuccessfulRewrite() {
+		rewriter = new ReconEntityRewriter(library, TestingData.newIdA);
+		library.setQid(4567L, "Q1234");
+		assertEquals(newlyCreated, rewriter.copy(TestingData.newIdB));
+	}
 
-    @Test
-    public void testSubjectNotRewriten() {
-        assertEquals(subject, rewriter.copy(subject));
-    }
+	@Test
+	public void testSubjectNotRewritten() {
+		ItemIdValue subject = TestingData.newIdA;
+		rewriter = new ReconEntityRewriter(library, subject);
+		assertEquals(subject, rewriter.copy(subject));
+	}
 
-    @Test
-    public void testMatched() {
-        assertEquals(TestingData.matchedId, rewriter.copy(TestingData.matchedId));
-    }
+	@Test
+	public void testSubjectRewritten() {
+		ItemIdValue subject = TestingData.newIdB;
+		library.setQid(4567L, "Q1234");
+		rewriter = new ReconEntityRewriter(library, subject);
+		assertEquals(newlyCreated, rewriter.copy(subject));
+	}
 
-    @Test
-    public void testRewriteUpdate() {
-        library.setQid(4567L, "Q1234");
-        ItemUpdate update = new ItemUpdateBuilder(subject)
-                .addStatement(TestingData.generateStatement(subject, TestingData.newIdB))
-                .deleteStatement(TestingData.generateStatement(subject, TestingData.existingId))
-                .addLabel(Datamodel.makeMonolingualTextValue("label", "de"), true)
-                .addDescription(Datamodel.makeMonolingualTextValue("beschreibung", "de"), false)
-                .addAlias(Datamodel.makeMonolingualTextValue("darstellung", "de")).build();
-        ItemUpdate rewritten = rewriter.rewrite(update);
-        ItemUpdate expected = new ItemUpdateBuilder(subject)
-                .addStatement(TestingData.generateStatement(subject, newlyCreated))
-                .deleteStatement(TestingData.generateStatement(subject, TestingData.existingId))
-                .addLabel(Datamodel.makeMonolingualTextValue("label", "de"), true)
-                .addDescription(Datamodel.makeMonolingualTextValue("beschreibung", "de"), false)
-                .addAlias(Datamodel.makeMonolingualTextValue("darstellung", "de")).build();
-        assertEquals(expected, rewritten);
-    }
+	@Test
+	public void testMatched() {
+		rewriter = new ReconEntityRewriter(library, TestingData.newIdA);
+		assertEquals(TestingData.matchedId, rewriter.copy(TestingData.matchedId));
+	}
+
+	@Test
+	public void testRewriteCreate() throws NewItemNotCreatedYetException {
+		ItemIdValue subject = TestingData.newIdA;
+		rewriter = new ReconEntityRewriter(library, subject);
+		library.setQid(4567L, "Q1234");
+		ItemUpdate update = new ItemUpdateBuilder(subject)
+				.addStatement(TestingData.generateStatement(subject, TestingData.newIdB))
+				.deleteStatement(TestingData.generateStatement(subject, TestingData.existingId))
+				.addLabel(Datamodel.makeMonolingualTextValue("label", "de"), true)
+				.addDescription(Datamodel.makeMonolingualTextValue("beschreibung", "de"), false)
+				.addAlias(Datamodel.makeMonolingualTextValue("darstellung", "de")).build();
+		ItemUpdate rewritten = rewriter.rewrite(update);
+		ItemUpdate expected = new ItemUpdateBuilder(subject)
+				.addStatement(TestingData.generateStatement(subject, newlyCreated))
+				.deleteStatement(TestingData.generateStatement(subject, TestingData.existingId))
+				.addLabel(Datamodel.makeMonolingualTextValue("label", "de"), true)
+				.addDescription(Datamodel.makeMonolingualTextValue("beschreibung", "de"), false)
+				.addAlias(Datamodel.makeMonolingualTextValue("darstellung", "de")).build();
+		assertEquals(rewritten, expected);
+	}
+
+	@Test
+	public void testRewriteUpdateOnPreviouslyCreatedEntity() throws NewItemNotCreatedYetException {
+		ItemIdValue subject = TestingData.newIdA;
+		rewriter = new ReconEntityRewriter(library, subject);
+		library.setQid(4567L, "Q1234");
+		ItemUpdate update = new ItemUpdateBuilder(TestingData.newIdB)
+				.addDescription(Datamodel.makeMonolingualTextValue("beschreibung", "de"), false)
+				.addAlias(Datamodel.makeMonolingualTextValue("darstellung", "de")).build();
+		ItemUpdate rewritten = rewriter.rewrite(update);
+		ItemUpdate expected = new ItemUpdateBuilder(newlyCreated)
+				.addDescription(Datamodel.makeMonolingualTextValue("beschreibung", "de"), false)
+				.addAlias(Datamodel.makeMonolingualTextValue("darstellung", "de")).build();
+		assertEquals(rewritten, expected);
+	}
+
+	@Test
+	public void testRewriteUpdateOnExistingEntity() throws NewItemNotCreatedYetException {
+		ItemIdValue subject = TestingData.matchedId;
+		rewriter = new ReconEntityRewriter(library, subject);
+		library.setQid(4567L, "Q1234");
+		ItemUpdate update = new ItemUpdateBuilder(subject)
+				.addStatement(TestingData.generateStatement(subject, TestingData.newIdB))
+				.deleteStatement(TestingData.generateStatement(subject, TestingData.existingId))
+				.addLabel(Datamodel.makeMonolingualTextValue("label", "de"), true)
+				.addDescription(Datamodel.makeMonolingualTextValue("beschreibung", "de"), false)
+				.addAlias(Datamodel.makeMonolingualTextValue("darstellung", "de")).build();
+		ItemUpdate rewritten = rewriter.rewrite(update);
+		ItemUpdate expected = new ItemUpdateBuilder(subject)
+				.addStatement(TestingData.generateStatement(subject, newlyCreated))
+				.deleteStatement(TestingData.generateStatement(subject, TestingData.existingId))
+				.addLabel(Datamodel.makeMonolingualTextValue("label", "de"), true)
+				.addDescription(Datamodel.makeMonolingualTextValue("beschreibung", "de"), false)
+				.addAlias(Datamodel.makeMonolingualTextValue("darstellung", "de")).build();
+		assertEquals(rewritten, expected);
+	}
 }