diff --git a/zulip/integrations/zephyr/check-mirroring b/zulip/integrations/zephyr/check-mirroring
index 67ccb249..bd49c805 100755
--- a/zulip/integrations/zephyr/check-mirroring
+++ b/zulip/integrations/zephyr/check-mirroring
@@ -228,6 +228,7 @@ def receive_zephyrs() -> None:
             logging.exception("Exception receiving zephyrs:")
             break
         if notice.z_opcode != b"":
+            zephyr_ctypes.ZFreeNotice(byref(notice))
             continue
         notices.append(notice)
 
@@ -335,6 +336,9 @@ z_contents = [
 (h_key_counts, h_missing_z, h_missing_h, h_duplicates, h_success) = process_keys(h_contents)
 (z_key_counts, z_missing_z, z_missing_h, z_duplicates, z_success) = process_keys(z_contents)
 
+for notice in notices:
+    zephyr_ctypes.ZFreeNotice(byref(notice))
+
 if z_success and h_success:
     logger.info("Success!")
     print_status_and_exit(0)
diff --git a/zulip/integrations/zephyr/zephyr_ctypes.py b/zulip/integrations/zephyr/zephyr_ctypes.py
index ef35f0a3..5817498b 100644
--- a/zulip/integrations/zephyr/zephyr_ctypes.py
+++ b/zulip/integrations/zephyr/zephyr_ctypes.py
@@ -167,6 +167,7 @@ ZGetSubscriptions = CFUNCTYPE(Code_t, POINTER(ZSubscription_t), POINTER(c_int))(
 )
 ZOpenPort = CFUNCTYPE(Code_t, POINTER(c_ushort))(("ZOpenPort", libzephyr))
 ZFlushSubscriptions = CFUNCTYPE(Code_t)(("ZFlushSubscriptions", libzephyr))
+ZFreeNotice = CFUNCTYPE(Code_t, POINTER(ZNotice_t))(("ZFreeNotice", libzephyr))
 ZSubscribeTo = CFUNCTYPE(Code_t, POINTER(ZSubscription_t), c_int, c_uint)(
     ("ZSubscribeTo", libzephyr)
 )
diff --git a/zulip/integrations/zephyr/zephyr_mirror_backend.py b/zulip/integrations/zephyr/zephyr_mirror_backend.py
index 2e906090..28adf7c2 100755
--- a/zulip/integrations/zephyr/zephyr_mirror_backend.py
+++ b/zulip/integrations/zephyr/zephyr_mirror_backend.py
@@ -321,13 +321,15 @@ def process_loop(zulip_queue: "Queue[ZephyrDict]", log: Optional[IO[str]]) -> No
                 notice = zephyr_ctypes.ZNotice_t()
                 sender = zephyr_ctypes.sockaddr_in()
                 zephyr_ctypes.check(zephyr_ctypes.ZReceiveNotice(byref(notice), byref(sender)))
-                recieve_backoff.succeed()
                 try:
+                    recieve_backoff.succeed()
                     process_notice(notice, zulip_queue, log)
                     process_backoff.succeed()
                 except zephyr_ctypes.ZephyrError:
                     logger.exception("Error relaying zephyr:")
                     process_backoff.fail()
+                finally:
+                    zephyr_ctypes.ZFreeNotice(byref(notice))
         except zephyr_ctypes.ZephyrError:
             logger.exception("Error checking for new zephyrs:")
             recieve_backoff.fail()