diff --git a/test/otel_metric_tests.exs b/test/otel_metric_tests.exs
index e377f30b..e5e20b18 100644
--- a/test/otel_metric_tests.exs
+++ b/test/otel_metric_tests.exs
@@ -1,5 +1,5 @@
 defmodule OtelMetricTests do
-  use ExUnit.Case, async: true
+  use ExUnit.Case, async: false
 
   require OpenTelemetryAPIExperimental.Counter, as: Counter
   require OpenTelemetryAPIExperimental.UpDownCounter, as: UpDownCounter
diff --git a/test/otel_tests.exs b/test/otel_tests.exs
index 6da0f584..786e0f65 100644
--- a/test/otel_tests.exs
+++ b/test/otel_tests.exs
@@ -1,5 +1,5 @@
 defmodule OtelTests do
-  use ExUnit.Case, async: true
+  use ExUnit.Case, async: false
 
   require OpenTelemetry.Tracer, as: Tracer
   require OpenTelemetry.Span, as: Span