diff --git a/modules/caddyhttp/tracing/module.go b/modules/caddyhttp/tracing/module.go
index c0c1566c2..20a54dde2 100644
--- a/modules/caddyhttp/tracing/module.go
+++ b/modules/caddyhttp/tracing/module.go
@@ -26,7 +26,7 @@ type Tracing struct {
 	// SpanName is a span name. It should follow the naming guidelines here:
 	// https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/trace/api.md#span
 	SpanName                 string `json:"span"`
-	InjectServerTimingHeader bool   `json:"injectServerTimingHeader"`
+	InjectServerTimingHeader bool   `json:"injectServerTimingHeader,omitempty"`
 
 	// otel implements opentelemetry related logic.
 	otel openTelemetryWrapper