diff --git a/zulip/integrations/rss/rss-bot b/zulip/integrations/rss/rss-bot
index a5833209..967db249 100755
--- a/zulip/integrations/rss/rss-bot
+++ b/zulip/integrations/rss/rss-bot
@@ -259,4 +259,4 @@ for feed_url in feed_urls:
         for hash in new_hashes:
             f.write(hash + "\n")
 
-    logger.info("Sent zulips for %d %s entries" % (len(new_hashes), feed_url))
+    logger.info("Sent zulips for %d %s entries", len(new_hashes), feed_url)
diff --git a/zulip/integrations/zephyr/check-mirroring b/zulip/integrations/zephyr/check-mirroring
index 63e715b9..150dda00 100755
--- a/zulip/integrations/zephyr/check-mirroring
+++ b/zulip/integrations/zephyr/check-mirroring
@@ -352,14 +352,22 @@ for key in all_keys:
     if key in zhkeys:
         (stream, test) = zhkeys[key]
         logger.warning(
-            "%10s: z got %s, h got %s.  Sent via Zephyr(%s): class %s"
-            % (key, z_key_counts[key], h_key_counts[key], test, stream)
+            "%10s: z got %s, h got %s.  Sent via Zephyr(%s): class %s",
+            key,
+            z_key_counts[key],
+            h_key_counts[key],
+            test,
+            stream,
         )
     if key in hzkeys:
         (stream, test) = hzkeys[key]
         logger.warning(
-            "%10s: z got %s. h got %s.  Sent via Zulip(%s): class %s"
-            % (key, z_key_counts[key], h_key_counts[key], test, stream)
+            "%10s: z got %s. h got %s.  Sent via Zulip(%s): class %s",
+            key,
+            z_key_counts[key],
+            h_key_counts[key],
+            test,
+            stream,
         )
 logger.error("")
 logger.error("Summary of specific problems:")
diff --git a/zulip/integrations/zephyr/zephyr_mirror_backend.py b/zulip/integrations/zephyr/zephyr_mirror_backend.py
index f140e104..eff51a8c 100755
--- a/zulip/integrations/zephyr/zephyr_mirror_backend.py
+++ b/zulip/integrations/zephyr/zephyr_mirror_backend.py
@@ -702,11 +702,9 @@ def send_zephyr(zwrite_args: List[str], content: str) -> Tuple[int, str]:
     stdout, stderr = p.communicate(input=content)
     if p.returncode:
         logger.error(
-            "zwrite command '%s' failed with return code %d:"
-            % (
-                " ".join(zwrite_args),
-                p.returncode,
-            )
+            "zwrite command %r failed with return code %d:",
+            zwrite_args,
+            p.returncode,
         )
         if stdout:
             logger.info("stdout: " + stdout)
diff --git a/zulip/zulip/cli.py b/zulip/zulip/cli.py
index 321c9425..170460b6 100755
--- a/zulip/zulip/cli.py
+++ b/zulip/zulip/cli.py
@@ -89,7 +89,7 @@ def send_message(recipients: List[str], stream: str, subject: str, message: str)
             message_data["subject"],
         )
     else:
-        log.info("Sending message to %s... " % message_data["to"])
+        log.info("Sending message to %s... ", message_data["to"])
     response = client.send_message(message_data)
     log_exit(response)