diff --git a/CHANGELOG.md b/CHANGELOG.md
index f450ea9da..1c94bdcbc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -132,3 +132,4 @@
 * [BUGFIX] runtimeconfig: Fix `runtime_config_last_reload_successful` metric after recovery from bad config with exact same config hash as before. #262
 * [BUGFIX] Ring status page: fixed the owned tokens percentage value displayed. #282
 * [BUGFIX] Ring: prevent iterating the whole ring when using `ExcludedZones`. #285
+* [BUGFIX] grpcclient: fix missing `.` in flag name for initial connection window size flag. #314
diff --git a/grpcclient/grpcclient.go b/grpcclient/grpcclient.go
index 53dccd8a3..09bf99733 100644
--- a/grpcclient/grpcclient.go
+++ b/grpcclient/grpcclient.go
@@ -59,7 +59,7 @@ func (cfg *Config) RegisterFlagsWithPrefix(prefix string, f *flag.FlagSet) {
 	f.IntVar(&cfg.RateLimitBurst, prefix+".grpc-client-rate-limit-burst", 0, "Rate limit burst for gRPC client.")
 	f.BoolVar(&cfg.BackoffOnRatelimits, prefix+".backoff-on-ratelimits", false, "Enable backoff and retry when we hit rate limits.")
 	f.Var(&cfg.InitialStreamWindowSize, prefix+".initial-stream-window-size", "Initial stream window size. Values less than the default are not supported and are ignored. Setting this to a value other than the default disables the BDP estimator.")
-	f.Var(&cfg.InitialConnectionWindowSize, prefix+"initial-connection-window-size", "Initial connection window size. Values less than the default are not supported and are ignored. Setting this to a value other than the default disables the BDP estimator.")
+	f.Var(&cfg.InitialConnectionWindowSize, prefix+".initial-connection-window-size", "Initial connection window size. Values less than the default are not supported and are ignored. Setting this to a value other than the default disables the BDP estimator.")
 	f.BoolVar(&cfg.TLSEnabled, prefix+".tls-enabled", cfg.TLSEnabled, "Enable TLS in the gRPC client. This flag needs to be enabled when any other TLS flag is set. If set to false, insecure connection to gRPC server will be used.")
 	f.DurationVar(&cfg.ConnectTimeout, prefix+".connect-timeout", 0, "The maximum amount of time to establish a connection. A value of 0 means default gRPC connect timeout and backoff.")
 	f.DurationVar(&cfg.ConnectBackoffBaseDelay, prefix+".connect-backoff-base-delay", time.Second, "Initial backoff delay after first connection failure. Only relevant if ConnectTimeout > 0.")