diff --git a/src/main/pumpnet/prinet-proxy/packet.c b/src/main/pumpnet/prinet-proxy/packet.c
index 200878b..9c99bb9 100644
--- a/src/main/pumpnet/prinet-proxy/packet.c
+++ b/src/main/pumpnet/prinet-proxy/packet.c
@@ -1,12 +1,26 @@
-#include <sodium.h>
-
 #include "pumpnet/prinet-proxy/packet.h"
 
 #include "util/log.h"
 #include "util/mem.h"
+#include "util/rand.h"
+
+struct pumpnet_prinet_proxy_packet_data {
+    uint32_t sequence_counter;
+    uint32_t packet_id;
+    uint8_t data[];
+} __attribute__((__packed__));
+
+struct pumpnet_prinet_proxy_packet_data_keepalive {
+    uint32_t unknown;
+} __attribute__((__packed__));
 
 static const size_t HEADER_SIZE = sizeof(uint32_t) + sizeof(uint8_t) * SEC_PRINET_NOUNCE_LEN;
 
+static const uint32_t PACKET_KEEPALIVE_ID = 0x3000000;
+static const uint32_t PACKET_KEEPALIVE_SIZE =
+        sizeof(struct pumpnet_prinet_proxy_packet_data) +
+        sizeof(struct pumpnet_prinet_proxy_packet_data_keepalive);
+
 struct pumpnet_prinet_proxy_packet* pumpnet_prinet_proxy_packet_alloc(size_t data_len)
 {
     struct pumpnet_prinet_proxy_packet* packet;
@@ -40,4 +54,23 @@ size_t pumpnet_prinet_proxy_packet_get_data_len(const struct pumpnet_prinet_prox
     }
 
     return packet->length - HEADER_SIZE;
+}
+
+struct pumpnet_prinet_proxy_packet* pumpnet_prinet_proxy_packet_create_keepalive()
+{
+    struct pumpnet_prinet_proxy_packet* packet;
+    struct pumpnet_prinet_proxy_packet_data* data;
+
+    packet = pumpnet_prinet_proxy_packet_alloc_response(PACKET_KEEPALIVE_SIZE);
+
+    util_rand_gen_bytes(packet->nounce, SEC_PRINET_NOUNCE_LEN);
+
+    data = (struct pumpnet_prinet_proxy_packet_data*) &packet->data;
+    // sequences always start with 1
+    data->sequence_counter = 1;
+    data->packet_id = PACKET_KEEPALIVE_ID;
+
+    // the data field of the keepalive packet is never read client-side
+
+    return packet;
 }
\ No newline at end of file
diff --git a/src/main/pumpnet/prinet-proxy/packet.h b/src/main/pumpnet/prinet-proxy/packet.h
index e73bb4f..578fafc 100644
--- a/src/main/pumpnet/prinet-proxy/packet.h
+++ b/src/main/pumpnet/prinet-proxy/packet.h
@@ -17,4 +17,6 @@ struct pumpnet_prinet_proxy_packet* pumpnet_prinet_proxy_packet_alloc_response(s
 
 size_t pumpnet_prinet_proxy_packet_get_header_len();
 
-size_t pumpnet_prinet_proxy_packet_get_data_len(const struct pumpnet_prinet_proxy_packet* packet);
\ No newline at end of file
+size_t pumpnet_prinet_proxy_packet_get_data_len(const struct pumpnet_prinet_proxy_packet* packet);
+
+struct pumpnet_prinet_proxy_packet* pumpnet_prinet_proxy_packet_create_keepalive();
\ No newline at end of file