diff --git a/src/tpm.c b/src/tpm.c
index d3b898d..22308f3 100644
--- a/src/tpm.c
+++ b/src/tpm.c
@@ -271,10 +271,12 @@ int tpm_pay(tolling_info_t* info, void** security_socket, uint8_t* neighbour, ui
             npr->network.choice.gn.securityProfile.encrypt = true;
             npr->network.choice.gn.securityProfile.sign = true;
 
-            npr->network.choice.gn.securityNeighbour = calloc(1, sizeof(OCTET_STRING_t));
-            npr->network.choice.gn.securityNeighbour->size = 8;
-            npr->network.choice.gn.securityNeighbour->buf = malloc(8);
-            memcpy(npr->network.choice.gn.securityNeighbour->buf, neighbour, 8);
+            if(neighbour){
+                npr->network.choice.gn.securityNeighbour = calloc(1, sizeof(OCTET_STRING_t));
+                npr->network.choice.gn.securityNeighbour->size = 8;
+                npr->network.choice.gn.securityNeighbour->buf = malloc(8);
+                memcpy(npr->network.choice.gn.securityNeighbour->buf, neighbour, 8);
+            }
 
             npr->data.size = tpm_uper_len;
             npr->data.buf = malloc(tpm_uper_len);
@@ -889,10 +891,12 @@ static int rsu_handle_recv(EI1_TPM_t* tpm_rx, void** security_socket, uint8_t* n
             npr->network.choice.gn.securityProfile.encrypt = true;
             npr->network.choice.gn.securityProfile.sign = true;
 
-            npr->network.choice.gn.securityNeighbour = calloc(1, sizeof(OCTET_STRING_t));
-            npr->network.choice.gn.securityNeighbour->size = 8;
-            npr->network.choice.gn.securityNeighbour->buf = malloc(8);
-            memcpy(npr->network.choice.gn.securityNeighbour->buf, neighbour, 8);
+            if(neighbour){
+                npr->network.choice.gn.securityNeighbour = calloc(1, sizeof(OCTET_STRING_t));
+                npr->network.choice.gn.securityNeighbour->size = 8;
+                npr->network.choice.gn.securityNeighbour->buf = malloc(8);
+                memcpy(npr->network.choice.gn.securityNeighbour->buf, neighbour, 8);
+            }
 
             npr->data.size = tpm_uper_len;
             npr->data.buf = malloc(tpm_uper_len);