diff --git a/src/capture_traffic.c b/src/capture_traffic.c
index d1f0522..c0bf6c3 100644
--- a/src/capture_traffic.c
+++ b/src/capture_traffic.c
@@ -61,12 +61,13 @@ void traffic_capture_stop(struct capture_ctx* ctx) {
 
   FILE* fd = NULL;
 
+  char *exts[] = {"emitted", "received"};
   struct dynbuf *dbs[] = {&ctx->in, &ctx->out};
   for (int i = 0; i < 2; i++) {
     size_t written = 0, ack = 0;
     char *out_file = NULL;
 
-    asprintf(&out_file, "%s.%d", ctx->filename, i);
+    asprintf(&out_file, "%s.%s", ctx->filename, exts[i]);
     if (out_file == NULL || (fd = fopen(out_file, "w")) == NULL) {
       perror("failed to open file");
       exit(EXIT_FAILURE);