diff --git a/src/main/java/com/solab/iso8583/codecs/CompositeField.java b/src/main/java/com/solab/iso8583/codecs/CompositeField.java
index 544fdf5..14418e5 100644
--- a/src/main/java/com/solab/iso8583/codecs/CompositeField.java
+++ b/src/main/java/com/solab/iso8583/codecs/CompositeField.java
@@ -53,7 +53,7 @@ public class CompositeField implements CustomBinaryField<CompositeField> {
 
     @SuppressWarnings("unchecked")
     public <T> IsoValue<T> getField(int idx) {
-        if (idx < 0 || idx > values.size())return null;
+        if (idx < 0 || idx >= values.size())return null;
         return values.get(idx);
     }
     public <T> T getObjectValue(int idx) {