diff --git a/main/src/com/google/refine/operations/cell/MassEditOperation.java b/main/src/com/google/refine/operations/cell/MassEditOperation.java
index fdd99d376..593912b42 100644
--- a/main/src/com/google/refine/operations/cell/MassEditOperation.java
+++ b/main/src/com/google/refine/operations/cell/MassEditOperation.java
@@ -77,7 +77,7 @@ public class MassEditOperation extends EngineDependentMassCellOperation {
             boolean fromError,
             Serializable to) {
             this.from = from;
-            this.fromBlank = fromBlank;
+            this.fromBlank = fromBlank || (from.size() == 1 && from.get(0).length() == 0);
             this.fromError = fromError;
             this.to = to;
         }
@@ -103,7 +103,16 @@ public class MassEditOperation extends EngineDependentMassCellOperation {
         }
     }
     
-    public MassEditOperation(EngineConfig engineConfig, String columnName, String expression, List<Edit> edits) {
+    @JsonCreator
+    public MassEditOperation(
+    		@JsonProperty("engineConfig")
+    		EngineConfig engineConfig,
+    		@JsonProperty("columnName")
+    		String columnName,
+    		@JsonProperty("expression")
+    		String expression,
+    		@JsonProperty("edits")
+    		List<Edit> edits) {
         super(engineConfig, columnName, true);
         _expression = expression;
         _edits = edits;
diff --git a/main/tests/server/src/com/google/refine/tests/operations/cell/MassOperationTests.java b/main/tests/server/src/com/google/refine/tests/operations/cell/MassOperationTests.java
index 01497bd5d..d604fedc3 100644
--- a/main/tests/server/src/com/google/refine/tests/operations/cell/MassOperationTests.java
+++ b/main/tests/server/src/com/google/refine/tests/operations/cell/MassOperationTests.java
@@ -93,7 +93,7 @@ public class MassOperationTests extends RefineTest {
     public void testReconstructEditDate() throws Exception {
       editsString = "[{\"from\":[\"2018-10-04T00:00:00Z\"],\"to\":\"newString\",\"type\":\"text\"}]";
 
-      editList = ParsingUtilities.mapper.readValue(ParsingUtilities.evaluateJsonStringToArray(editsString).toString(), new TypeReference<List<Edit>>() {});
+      editList = ParsingUtilities.mapper.readValue(editsString, new TypeReference<List<Edit>>() {});
 
       Assert.assertEquals(editList.get(0).from.get(0), "2018-10-04T00:00:00Z");
       Assert.assertEquals(editList.get(0).to,"newString" );
@@ -105,7 +105,7 @@ public class MassOperationTests extends RefineTest {
     public void testReconstructEditEmpty() throws Exception {
       editsString = "[{\"from\":[\"\"],\"to\":\"newString\",\"type\":\"text\"}]";
 
-      editList = ParsingUtilities.mapper.readValue(ParsingUtilities.evaluateJsonStringToArray(editsString).toString(), new TypeReference<List<Edit>>() {});
+      editList = ParsingUtilities.mapper.readValue(editsString, new TypeReference<List<Edit>>() {});
 
       Assert.assertEquals(editList.get(0).from.size(), 1);
       Assert.assertEquals(editList.get(0).from.get(0), "");