diff --git a/src/Libraries/Microsoft.Extensions.AI/OpenTelemetryConsts.cs b/src/Libraries/Microsoft.Extensions.AI/OpenTelemetryConsts.cs
index d2fefa64002..dc914fca427 100644
--- a/src/Libraries/Microsoft.Extensions.AI/OpenTelemetryConsts.cs
+++ b/src/Libraries/Microsoft.Extensions.AI/OpenTelemetryConsts.cs
@@ -11,7 +11,7 @@ internal static class OpenTelemetryConsts
     public const string DefaultSourceName = "Experimental.Microsoft.Extensions.AI";
 
     public const string SecondsUnit = "s";
-    public const string TokensUnit = "token";
+    public const string TokensUnit = "{token}";
 
     /// <summary>Environment variable name for controlling whether sensitive content should be captured in telemetry by default.</summary>
     public const string GenAICaptureMessageContentEnvVar = "OTEL_INSTRUMENTATION_GENAI_CAPTURE_MESSAGE_CONTENT";