diff --git a/clients/c/cosmopolite.c b/clients/c/cosmopolite.c
index 58aff61..72ab98d 100644
--- a/clients/c/cosmopolite.c
+++ b/clients/c/cosmopolite.c
@@ -97,7 +97,6 @@ static bool cosmo_send_http_int(cosmo *instance, cosmo_transfer *transfer) {
   long return_code;
   assert(curl_easy_getinfo(instance->curl, CURLINFO_RESPONSE_CODE, &return_code) == CURLE_OK);
   if (return_code != 200) {
-    fprintf(stderr, "server returned error: %ld\n", return_code);
     return false;
   }
 
@@ -229,6 +228,7 @@ static json_t *cosmo_send_rpc(cosmo *instance, json_t *commands, json_t *ack) {
   char *profile;
   if (json_unpack(received, "{sssoso}", "profile", &profile, "responses", &command_responses, "events", &events)) {
     fprintf(stderr, "invalid server response\n");
+    json_decref(received);
     return commands;
   }
 
@@ -249,7 +249,38 @@ static json_t *cosmo_send_rpc(cosmo *instance, json_t *commands, json_t *ack) {
     fprintf(stderr, "invalid poll response\n");
   } else {
     if (new_poll) {
-      // TODO: resubscribe to ACTIVE subscriptions
+      assert(!pthread_mutex_lock(&instance->lock));
+      size_t i;
+      json_t *subscription;
+      json_array_foreach(instance->subscriptions, i, subscription) {
+        int state;
+        json_t *subject, *messages;
+        assert(!json_unpack(subscription, "{sisoso}", "state", &state, "subject", &subject, "messages", &messages));
+
+        if (state == SUBSCRIPTION_PENDING) {
+          continue;
+        }
+
+        json_t *arguments = json_pack("{sO}", "subject", subject);
+        if (json_array_size(messages)) {
+          // Restart at the last actual ID we received.
+          json_t *last_message = json_array_get(messages, json_array_size(messages) - 1);
+          json_object_set(arguments, "last_id", json_object_get(last_message, "id"));
+        } else {
+          json_t *num_messages = json_object_get(subscription, "num_messages");
+          if (num_messages) {
+            json_object_set(arguments, "messages", num_messages);
+          }
+          json_t *last_id = json_object_get(subscription, "last_id");
+          if (last_id) {
+            json_object_set(arguments, "last_id", last_id);
+          }
+        }
+
+        json_array_append_new(instance->command_queue, cosmo_command("subscribe", arguments));
+        instance->next_delay_ms = 0;
+      }
+      assert(!pthread_mutex_unlock(&instance->lock));
     }
   }
 
@@ -368,7 +399,7 @@ void cosmo_subscribe(cosmo *instance, json_t *subject, const json_int_t messages
   json_t *arguments = json_pack("{sO}", "subject", subject);
   if (messages) {
     json_object_set_new(arguments, "messages", json_integer(messages));
-    json_object_set_new(subscription, "messages", json_integer(messages));
+    json_object_set_new(subscription, "num_messages", json_integer(messages));
   }
   if (last_id) {
     json_object_set_new(arguments, "last_id", json_integer(last_id));
diff --git a/clients/c/test.c b/clients/c/test.c
index 17b6884..6f8590b 100644
--- a/clients/c/test.c
+++ b/clients/c/test.c
@@ -142,10 +142,38 @@ bool test_logout_fires(test_state *state) {
   return true;
 }
 
+bool test_resubscribe(test_state *state) {
+  cosmo *client = create_client(state);
+
+  json_t *subject = random_subject(NULL, NULL);
+  cosmo_subscribe(client, subject, -1, 0);
+
+  json_t *message_out = random_message();
+  cosmo_send_message(client, subject, message_out);
+  const json_t *message_in = wait_for_message(state);
+  assert(json_equal(message_out, json_object_get(message_in, "message")));
+  json_decref(message_out);
+
+  // Reach in and reset the instance ID so we look new.
+  cosmo_uuid(client->instance_id);
+
+  message_out = random_message();
+  cosmo_send_message(client, subject, message_out);
+  message_in = wait_for_message(state);
+  assert(json_equal(message_out, json_object_get(message_in, "message")));
+  json_decref(message_out);
+
+  json_decref(subject);
+
+  cosmo_shutdown(client);
+  return true;
+}
+
 int main(int argc, char *argv[]) {
   RUN_TEST(test_create_destroy);
   RUN_TEST(test_message_round_trip);
   RUN_TEST(test_logout_fires);
+  RUN_TEST(test_resubscribe);
 
   return 0;
 }