diff --git a/LibAPRS/AX25.h b/LibAPRS/AX25.h
index fae90f6..4a453d8 100644
--- a/LibAPRS/AX25.h
+++ b/LibAPRS/AX25.h
@@ -7,7 +7,7 @@
 
 #define AX25_MIN_FRAME_LEN 18
 #ifndef CUSTOM_FRAME_SIZE
-    #define AX25_MAX_FRAME_LEN 620
+    #define AX25_MAX_FRAME_LEN 330
 #else
     #define AX25_MAX_FRAME_LEN CUSTOM_FRAME_SIZE
 #endif