diff --git a/src/main/java/com/solab/iso8583/MessageFactory.java b/src/main/java/com/solab/iso8583/MessageFactory.java
index f5b751d..6777d78 100644
--- a/src/main/java/com/solab/iso8583/MessageFactory.java
+++ b/src/main/java/com/solab/iso8583/MessageFactory.java
@@ -362,7 +362,7 @@ public class MessageFactory<T extends IsoMessage> {
                         bs.set(pos++, ((bitmapBuffer[i] - 55) & 8) > 0);
                         bs.set(pos++, ((bitmapBuffer[i] - 55) & 4) > 0);
                         bs.set(pos++, ((bitmapBuffer[i] - 55) & 2) > 0);
-                        bs.set(pos++, ((bitmapBuffer[i] - 5) & 1) > 0);
+                        bs.set(pos++, ((bitmapBuffer[i] - 55) & 1) > 0);
                     } else if (bitmapBuffer[i] >= 'a' && bitmapBuffer[i] <= 'f') {
                         bs.set(pos++, ((bitmapBuffer[i] - 87) & 8) > 0);
                         bs.set(pos++, ((bitmapBuffer[i] - 87) & 4) > 0);