diff --git a/src/main/java/com/solab/iso8583/IsoMessage.java b/src/main/java/com/solab/iso8583/IsoMessage.java
index 062c0a7..90c3d89 100644
--- a/src/main/java/com/solab/iso8583/IsoMessage.java
+++ b/src/main/java/com/solab/iso8583/IsoMessage.java
@@ -355,7 +355,7 @@ public class IsoMessage {
     	for (int i : idx) {
     		IsoValue<?> v = src.getField(i);
     		if (v != null) {
-        		setValue(i, v.getValue(), v.getType(), v.getLength());
+        		setValue(i, v.getValue(), v.getEncoder(), v.getType(), v.getLength());
     		}
     	}
     }
diff --git a/src/main/java/com/solab/iso8583/IsoValue.java b/src/main/java/com/solab/iso8583/IsoValue.java
index add7791..687d971 100644
--- a/src/main/java/com/solab/iso8583/IsoValue.java
+++ b/src/main/java/com/solab/iso8583/IsoValue.java
@@ -177,6 +177,11 @@ public class IsoValue<T> implements Cloneable {
 		return value == null ? 0 : toString().hashCode();
 	}
 
+	/** Returns the CustomField encoder for this value. */
+	public CustomField<T> getEncoder() {
+		return encoder;
+	}
+
 	/** Writes the formatted value to a stream, with the length header
 	 * if it's a variable length type. */
 	public void write(OutputStream outs, boolean binary) throws IOException {