diff --git a/clatd.h b/clatd.h
index f421f46..126a31c 100644
--- a/clatd.h
+++ b/clatd.h
@@ -21,7 +21,8 @@
 #include <sys/uio.h>
 
 #define MAXMTU 1500
-#define PACKETLEN (MAXMTU+sizeof(struct tun_pi))
+#define MAXMRU 65536
+#define PACKETLEN (MAXMRU+sizeof(struct tun_pi))
 #define CLATD_VERSION "1.4"
 
 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
diff --git a/clatd_test.cpp b/clatd_test.cpp
index 6e374d2..d67113f 100644
--- a/clatd_test.cpp
+++ b/clatd_test.cpp
@@ -486,7 +486,7 @@
 
 void check_translated_packet(const uint8_t *original, size_t original_len,
                              const uint8_t *expected, size_t expected_len, const char *msg) {
-  uint8_t translated[MAXMTU];
+  uint8_t translated[MAXMRU];
   size_t translated_len = sizeof(translated);
   do_translate_packet(original, original_len, translated, &translated_len, msg);
   EXPECT_EQ(expected_len, translated_len) << msg << ": Translated packet length incorrect\n";
@@ -505,12 +505,12 @@
   }
 
   // Sanity check that reassembling the original and translated fragments produces valid packets.
-  uint8_t reassembled[MAXMTU];
+  uint8_t reassembled[MAXMRU];
   size_t reassembled_len = sizeof(reassembled);
   reassemble_packet(original, original_lengths, numfragments, reassembled, &reassembled_len, msg);
   check_packet(reassembled, reassembled_len, msg);
 
-  uint8_t translated[MAXMTU];
+  uint8_t translated[MAXMRU];
   size_t translated_len = sizeof(translated);
   do_translate_packet(reassembled, reassembled_len, translated, &translated_len, msg);
   check_packet(translated, translated_len, msg);
@@ -772,7 +772,7 @@
   check_packet(ipv6_ping, sizeof(ipv6_ping), "IPv6 ping sanity check");
 
   // Sanity checks reassemble_packet.
-  uint8_t reassembled[MAXMTU];
+  uint8_t reassembled[MAXMRU];
   size_t total_length = sizeof(reassembled);
   reassemble_packet(kIPv4Fragments, kIPv4FragLengths, ARRAYSIZE(kIPv4Fragments),
                     reassembled, &total_length, "Reassembly sanity check");
@@ -898,7 +898,7 @@
 
 void check_translate_checksum_neutral(const uint8_t *original, size_t original_len,
                                       size_t expected_len, const char *msg) {
-  uint8_t translated[MAXMTU];
+  uint8_t translated[MAXMRU];
   size_t translated_len = sizeof(translated);
   do_translate_packet(original, original_len, translated, &translated_len, msg);
   EXPECT_EQ(expected_len, translated_len) << msg << ": Translated packet length incorrect\n";
diff --git a/ring.h b/ring.h
index 9e517be..20d2f98 100644
--- a/ring.h
+++ b/ring.h
@@ -27,10 +27,10 @@
 
 // Frame size. Must be a multiple of TPACKET_ALIGNMENT (=16)
 // Why the 16? http://lxr.free-electrons.com/source/net/packet/af_packet.c?v=3.4#L1764
-#define TP_FRAME_SIZE (TPACKET_ALIGN(MAXMTU) + TPACKET_ALIGN(TPACKET2_HDRLEN) + 16)
+#define TP_FRAME_SIZE (TPACKET_ALIGN(MAXMRU) + TPACKET_ALIGN(TPACKET2_HDRLEN) + 16)
 
 // Block size. Must be a multiple of the page size, and a power of two for efficient memory use.
-#define TP_BLOCK_SIZE 65536
+#define TP_BLOCK_SIZE 2686976
 
 // In order to save memory, our frames are not an exact divider of the block size. Therefore, the
 // mmaped region will have gaps corresponding to the empty space at the end of each block.