diff --git a/rfc8416.php b/rfc8416.php
index b526828..2924e48 100755
--- a/rfc8416.php
+++ b/rfc8416.php
@@ -91,7 +91,7 @@ foreach ($raw_array as $sub_array)
     $_maxlength = (isset ($maxlength[0]) ? $maxlength[0] : "");
   else
     // Do fallback to default prefix size if max-length was not set.
-    $_maxlength = $prefix[2];
+    $_maxlength = ($prefix[2] < 64 ? 64 : $prefix[2]);
   
   $_mnt = $mnt[0];
 
@@ -190,7 +190,7 @@ foreach ($raw_array as $sub_array)
     $_maxlength = (isset ($maxlength[0]) ? $maxlength[0] : "");
   else
     // Do fallback to default prefix size if max-length was not set.
-    $_maxlength = $prefix[2];
+    $_maxlength = ($prefix[2] < 29 ? 29 : $prefix[2]);
 
   $_mnt = $mnt[0];
   
diff --git a/roagen.php b/roagen.php
index 129d7c2..761712a 100755
--- a/roagen.php
+++ b/roagen.php
@@ -77,7 +77,7 @@ foreach ($raw_array as $sub_array)
     $_maxlength = (isset ($maxlength[0]) ? $maxlength[0] : "");
   else
     // Do fallback to default prefix size if max-length was not set.
-    $_maxlength = $prefix[2];
+    $_maxlength = ($prefix[2] < 64 ? 64 : $prefix[2]);
 
   // Loop through each asn in single route6 object and assign
   // other values accordingly.
@@ -167,7 +167,7 @@ foreach ($raw_array as $sub_array)
     $_maxlength = (isset ($maxlength[0]) ? $maxlength[0] : "");
   else
     // Do fallback to default prefix size if max-length was not set.
-    $_maxlength = $prefix[2];
+    $_maxlength = ($prefix[2] < 29 ? 29 : $prefix[2]);
 
   // Loop through each asn in single route6 object and assign
   // other values accordingly.