diff --git a/management/ssl_certificates.py b/management/ssl_certificates.py
index 5b9470ec..db36234c 100755
--- a/management/ssl_certificates.py
+++ b/management/ssl_certificates.py
@@ -515,7 +515,7 @@ def check_certificate(domain, ssl_certificate, ssl_private_key, warn_if_expiring
 		cert = load_pem(ssl_cert_chain[0])
 		if not isinstance(cert, Certificate): raise ValueError("This is not a certificate file.")
 	except ValueError as e:
-		return (f"There is a problem with the certificate file: {str(e)}", None)
+		return (f"There is a problem with the certificate file: {e!s}", None)
 
 	# First check that the domain name is one of the names allowed by
 	# the certificate.
diff --git a/management/status_checks.py b/management/status_checks.py
index b584f9e1..bfc820df 100755
--- a/management/status_checks.py
+++ b/management/status_checks.py
@@ -248,7 +248,7 @@ def check_free_disk_space(rounded_values, env, output):
 def check_free_memory(rounded_values, env, output):
 	# Check free memory.
 	percent_free = 100 - psutil.virtual_memory().percent
-	memory_msg = f"System memory is {str(round(percent_free))}% free."
+	memory_msg = f"System memory is {round(percent_free)!s}% free."
 	if percent_free >= 20:
 		if rounded_values: memory_msg = "System free memory is at least 20%."
 		output.print_ok(memory_msg)