diff --git a/apps/opentelemetry_api/lib/open_telemetry/tracer.ex b/apps/opentelemetry_api/lib/open_telemetry/tracer.ex
index e67ee33e..f786d598 100644
--- a/apps/opentelemetry_api/lib/open_telemetry/tracer.ex
+++ b/apps/opentelemetry_api/lib/open_telemetry/tracer.ex
@@ -121,8 +121,7 @@ defmodule OpenTelemetry.Tracer do
 
   The Span in the current Context has its `is_recording` set to `false`.
   """
-  @spec end_span(:opentelemetry.timestamp() | :undefined) ::
-          :opentelemetry.span_ctx() | :undefined
+  @spec end_span(:opentelemetry.timestamp() | :undefined) :: :opentelemetry.span_ctx()
   def end_span(timestamp \\ :undefined) do
     non_recording_span = :otel_span.end_span(:otel_tracer.current_span_ctx(), timestamp)
     _ = :otel_tracer.set_current_span(non_recording_span)