diff --git a/src/main/java/com/solab/iso8583/IsoMessage.java b/src/main/java/com/solab/iso8583/IsoMessage.java
index 70b04d4..855ec19 100644
--- a/src/main/java/com/solab/iso8583/IsoMessage.java
+++ b/src/main/java/com/solab/iso8583/IsoMessage.java
@@ -152,8 +152,7 @@ public class IsoMessage {
      * @param t The ISO type.
      * @param length The length of the field, used for ALPHA and NUMERIC values only, ignored
      * with any other type. */
-	@SuppressWarnings("unchecked")
-    public void setValue(int index, Object value, CustomField<?> encoder, IsoType t, int length) {
+    public <T> void setValue(int index, T value, CustomField<T> encoder, IsoType t, int length) {
     	if (index < 2 || index > 128) {
     		throw new IndexOutOfBoundsException("Field index must be between 2 and 128");
     	}
@@ -162,9 +161,9 @@ public class IsoMessage {
     	} else {
     		IsoValue v = null;
     		if (t.needsLength()) {
-    			v = new IsoValue(t, value, length, encoder);
+    			v = new IsoValue<T>(t, value, length, encoder);
     		} else {
-    			v = new IsoValue(t, value, encoder);
+    			v = new IsoValue<T>(t, value, encoder);
     		}
     		v.setCharacterEncoding(encoding);
     		fields[index] = v;
@@ -375,7 +374,7 @@ public class IsoMessage {
      * not present in the source message it is simply ignored. */
     public void copyFieldsFrom(IsoMessage src, int...idx) {
     	for (int i : idx) {
-    		IsoValue<?> v = src.getField(i);
+    		IsoValue<Object> v = src.getField(i);
     		if (v == null) {
     			setField(i, null);
     		} else {
diff --git a/src/main/java/com/solab/iso8583/MessageFactory.java b/src/main/java/com/solab/iso8583/MessageFactory.java
index 8cb0c40..0dd496f 100644
--- a/src/main/java/com/solab/iso8583/MessageFactory.java
+++ b/src/main/java/com/solab/iso8583/MessageFactory.java
@@ -64,7 +64,7 @@ public class MessageFactory {
 	/** The ISO header to be included in each message type. */
 	private Map<Integer, String> isoHeaders = new HashMap<Integer, String>();
 	/** A map for the custom field encoder/decoders, keyed by field number. */
-	private Map<Integer, CustomField<?>> customFields = new HashMap<Integer, CustomField<?>>();
+	private Map<Integer, CustomField> customFields = new HashMap<Integer, CustomField>();
 	/** Indicates if the current date should be set on new messages (field 7). */
 	private boolean setDate;
 	/** Indicates if the factory should create binary messages and also parse binary messages. */
@@ -116,7 +116,7 @@ public class MessageFactory {
 	}
 
 	/** Specifies a map for custom field encoder/decoders. The keys are the field numbers. */
-	public void setCustomFields(Map<Integer, CustomField<?>> value) {
+	public void setCustomFields(Map<Integer, CustomField> value) {
 		customFields = value;
 	}
 
@@ -125,11 +125,13 @@ public class MessageFactory {
 		customFields.put(index, value);
 	}
 	/** Returns a custom field encoder/decoder for the specified field number, if one is available. */
-	public CustomField<?> getCustomField(int index) {
+	@SuppressWarnings("unchecked")
+	public <T> CustomField<T> getCustomField(int index) {
 		return customFields.get(index);
 	}
 	/** Returns a custom field encoder/decoder for the specified field number, if one is available. */
-	public CustomField<?> getCustomField(Integer index) {
+	@SuppressWarnings("unchecked")
+	public <T> CustomField<T> getCustomField(Integer index) {
 		return customFields.get(index);
 	}
 
diff --git a/src/main/java/com/solab/iso8583/parse/ConfigParser.java b/src/main/java/com/solab/iso8583/parse/ConfigParser.java
index 2144b98..fb76749 100644
--- a/src/main/java/com/solab/iso8583/parse/ConfigParser.java
+++ b/src/main/java/com/solab/iso8583/parse/ConfigParser.java
@@ -147,7 +147,7 @@ public class ConfigParser {
 					length = Integer.parseInt(f.getAttribute("length"));
 				}
 				String v = f.getChildNodes().item(0).getNodeValue();
-				CustomField<?> _cf = mfact.getCustomField(num);
+				CustomField<Object> _cf = mfact.getCustomField(num);
 				m.setValue(num, _cf == null ? v : _cf.decodeField(v), _cf, itype, length);
 			}
 			mfact.addMessageTemplate(m);