diff --git a/extensions/wikidata/src/org/openrefine/wikidata/operations/PerformWikibaseEditsOperation.java b/extensions/wikidata/src/org/openrefine/wikidata/operations/PerformWikibaseEditsOperation.java
index 3154b4fbc..218d331ac 100644
--- a/extensions/wikidata/src/org/openrefine/wikidata/operations/PerformWikibaseEditsOperation.java
+++ b/extensions/wikidata/src/org/openrefine/wikidata/operations/PerformWikibaseEditsOperation.java
@@ -75,28 +75,6 @@ public class PerformWikibaseEditsOperation extends EngineDependentOperation {
         Validate.notEmpty(summary, "An edit summary must be provided.");
         this.summary = summary;
     }
-    
-    /* The constructor above should be enough for deserialization,
-     * but for some unknown reason it can fail in certain cases
-     * (might be due to caching deserializers across threads?)
-     * 
-     * So we sadly add a default constructor and a setter below.
-     * 
-     * TODO delete the default constructor and setter, make summary final
-     */
-    public PerformWikibaseEditsOperation() {
-    	super(null);
-    }
-    
-    @JsonProperty("engineConfig")
-    public void setEngineConfig(EngineConfig config) {
-    	this._engineConfig = config;
-    }
-    
-    @JsonProperty("summary")
-    public void setSummary(String summary) {
-    	this.summary = summary;
-    }
 
     @Override
     protected String getBriefDescription(Project project) {
diff --git a/extensions/wikidata/src/org/openrefine/wikidata/operations/SaveWikibaseSchemaOperation.java b/extensions/wikidata/src/org/openrefine/wikidata/operations/SaveWikibaseSchemaOperation.java
index 0ab7fe934..3d7aa938c 100644
--- a/extensions/wikidata/src/org/openrefine/wikidata/operations/SaveWikibaseSchemaOperation.java
+++ b/extensions/wikidata/src/org/openrefine/wikidata/operations/SaveWikibaseSchemaOperation.java
@@ -46,30 +46,14 @@ public class SaveWikibaseSchemaOperation extends AbstractOperation {
     @JsonIgnore
     final public static String operationDescription = "Save Wikibase schema";
     @JsonProperty("schema")
-    protected WikibaseSchema _schema;
+    final protected WikibaseSchema _schema;
 
     @JsonCreator
     public SaveWikibaseSchemaOperation(
     		@JsonProperty("schema")
     		WikibaseSchema schema) {
         this._schema = schema;
-    }
-    
-    /* The constructor above should be enough for deserialization,
-     * but for some unknown reason it can fail in certain cases
-     * (might be due to caching deserializers across threads?)
-     * 
-     * So we sadly add a default constructor and a setter below.
-     * 
-     * TODO delete the default constructor and setter, make schema final
-     */
-    public SaveWikibaseSchemaOperation() {
-    	
-    }
-    
-    @JsonProperty("schema")
-    public void setSchema(WikibaseSchema schema) {
-    	this._schema = schema;
+
     }
 
     @Override