diff --git a/src/main/java/com/github/jcustenborder/kafka/connect/transform/common/PatternMapString.java b/src/main/java/com/github/jcustenborder/kafka/connect/transform/common/PatternMapString.java
index 852fbf7..4828029 100644
--- a/src/main/java/com/github/jcustenborder/kafka/connect/transform/common/PatternMapString.java
+++ b/src/main/java/com/github/jcustenborder/kafka/connect/transform/common/PatternMapString.java
@@ -85,7 +85,7 @@ protected SchemaAndValue processStruct(R record, Schema inputSchema, Struct inpu
         final String inputFieldName = inputField.name();
         final Object value = inputStruct.get(inputFieldName);
         outputStruct.put(inputFieldName, value);
-        if (inputFieldName.equals(config.srcfieldname)) {
+        if (inputFieldName.equals(config.srcfieldname) && value != null) {
           String replacedField = (String) value;
           final Matcher fieldMatcher = this.config.pattern.matcher(replacedField);
           String replacedValue = fieldMatcher.replaceAll(this.config.replacement);
@@ -109,6 +109,8 @@ protected SchemaAndValue processStruct(R record, Schema inputSchema, Struct inpu
         }
         outputStruct.put(config.destfieldname, replacedValue);
         retVal = new SchemaAndValue(outPutSchema, outputStruct);
+      } else {
+        retVal = new SchemaAndValue(outPutSchema, inputStruct);
       }
     }
     return retVal;
diff --git a/src/test/java/com/github/jcustenborder/kafka/connect/transform/common/PatternMapStringTest.java b/src/test/java/com/github/jcustenborder/kafka/connect/transform/common/PatternMapStringTest.java
index 9037b57..c11f4d8 100644
--- a/src/test/java/com/github/jcustenborder/kafka/connect/transform/common/PatternMapStringTest.java
+++ b/src/test/java/com/github/jcustenborder/kafka/connect/transform/common/PatternMapStringTest.java
@@ -276,6 +276,105 @@ public void multiple() {
     assertStruct(expectedStruct, actualStruct);
   }
 
+  @Test
+  public void missingFieldWithoutRename() {
+    this.transformation.configure(
+            ImmutableMap.of(
+                    PatternMapStringConfig.SRC_FIELD_NAME_CONF, "fieldA",
+                    PatternMapStringConfig.DEST_FIELD_NAME_CONF, "fieldA",
+                    PatternMapStringConfig.VALUE_PATTERN_CONF, "from",
+                    PatternMapStringConfig.VALUE_REPLACEMENT_CONF, "to"
+            )
+    );
+
+    Schema inputSchema = SchemaBuilder.struct()
+            .name("testing")
+            .field("fieldA", Schema.OPTIONAL_STRING_SCHEMA)
+            .field("fieldB", Schema.STRING_SCHEMA);
+    Struct inputStruct = new Struct(inputSchema)
+            .put("fieldB", "valueB");
+
+    final Object key = isKey ? inputStruct : null;
+    final Object value = isKey ? null : inputStruct;
+    final Schema keySchema = isKey ? inputSchema : null;
+    final Schema valueSchema = isKey ? null : inputSchema;
+
+    final SinkRecord inputRecord = new SinkRecord(
+            TOPIC,
+            1,
+            keySchema,
+            key,
+            valueSchema,
+            value,
+            1234L
+    );
+    final SinkRecord outputRecord = this.transformation.apply(inputRecord);
+    assertNotNull(outputRecord);
+
+    final Schema actualSchema = isKey ? outputRecord.keySchema() : outputRecord.valueSchema();
+    final Struct actualStruct = (Struct) (isKey ? outputRecord.key() : outputRecord.value());
+
+    final Schema expectedSchema = SchemaBuilder.struct()
+            .name("testing")
+            .field("fieldA", Schema.OPTIONAL_STRING_SCHEMA)
+            .field("fieldB", Schema.STRING_SCHEMA);
+    Struct expectedStruct = new Struct(expectedSchema)
+            .put("fieldB", "valueB");
+
+    assertSchema(expectedSchema, actualSchema);
+    assertStruct(expectedStruct, actualStruct);
+  }
+
+  @Test
+  public void missingFieldWithRename() {
+    this.transformation.configure(
+            ImmutableMap.of(
+                    PatternMapStringConfig.SRC_FIELD_NAME_CONF, "fieldA",
+                    PatternMapStringConfig.DEST_FIELD_NAME_CONF, "fieldC",
+                    PatternMapStringConfig.VALUE_PATTERN_CONF, "from",
+                    PatternMapStringConfig.VALUE_REPLACEMENT_CONF, "to"
+            )
+    );
+
+    Schema inputSchema = SchemaBuilder.struct()
+            .name("testing")
+            .field("fieldA", Schema.OPTIONAL_STRING_SCHEMA)
+            .field("fieldB", Schema.STRING_SCHEMA);
+    Struct inputStruct = new Struct(inputSchema)
+            .put("fieldB", "valueB");
+
+    final Object key = isKey ? inputStruct : null;
+    final Object value = isKey ? null : inputStruct;
+    final Schema keySchema = isKey ? inputSchema : null;
+    final Schema valueSchema = isKey ? null : inputSchema;
+
+    final SinkRecord inputRecord = new SinkRecord(
+            TOPIC,
+            1,
+            keySchema,
+            key,
+            valueSchema,
+            value,
+            1234L
+    );
+    final SinkRecord outputRecord = this.transformation.apply(inputRecord);
+    assertNotNull(outputRecord);
+
+    final Schema actualSchema = isKey ? outputRecord.keySchema() : outputRecord.valueSchema();
+    final Struct actualStruct = (Struct) (isKey ? outputRecord.key() : outputRecord.value());
+
+    final Schema expectedSchema = SchemaBuilder.struct()
+            .name("testing")
+            .field("fieldA", Schema.OPTIONAL_STRING_SCHEMA)
+            .field("fieldC", Schema.OPTIONAL_STRING_SCHEMA)
+            .field("fieldB", Schema.STRING_SCHEMA);
+    Struct expectedStruct = new Struct(expectedSchema)
+            .put("fieldB", "valueB");
+
+    assertSchema(expectedSchema, actualSchema);
+    assertStruct(expectedStruct, actualStruct);
+  }
+
 
   public static class KeyTest<R extends ConnectRecord<R>> extends PatternMapStringTest {
     protected KeyTest() {