diff --git a/proxy/http/proxy/server.py b/proxy/http/proxy/server.py
index 4e2f44ac3f..70d3369ec4 100644
--- a/proxy/http/proxy/server.py
+++ b/proxy/http/proxy/server.py
@@ -726,9 +726,9 @@ def generate_upstream_certificate(
         ):
             raise HttpProtocolException(
                 f'For certificate generation all the following flags are mandatory: '
-                f'--ca-cert-file:{ self.flags.ca_cert_file}, '
-                f'--ca-key-file:{ self.flags.ca_key_file}, '
-                f'--ca-signing-key-file:{ self.flags.ca_signing_key_file}',
+                f'--ca-cert-file:{ self.flags.ca_cert_file }, '
+                f'--ca-key-file:{ self.flags.ca_key_file }, '
+                f'--ca-signing-key-file:{ self.flags.ca_signing_key_file }',
             )
         cert_file_path = HttpProxyPlugin.generated_cert_file_path(
             self.flags.ca_cert_dir, text_(self.request.host),
diff --git a/proxy/http/websocket/frame.py b/proxy/http/websocket/frame.py
index 08954f0725..af6e0c7e9e 100644
--- a/proxy/http/websocket/frame.py
+++ b/proxy/http/websocket/frame.py
@@ -128,8 +128,8 @@ def build(self) -> bytes:
             )
         else:
             raise ValueError(
-                f'Invalid payload_length { self.payload_length},'
-                f'maximum allowed { 1 << 64}',
+                f'Invalid payload_length { self.payload_length },'
+                f'maximum allowed { 1 << 64 }',
             )
         if self.masked and self.data:
             mask = secrets.token_bytes(4) if self.mask is None else self.mask