diff --git a/src/Shared/LayoutRenderers/AspNetRequestDurationLayoutRenderer.cs b/src/Shared/LayoutRenderers/AspNetRequestDurationLayoutRenderer.cs
index 4ad2c50c..774ed525 100644
--- a/src/Shared/LayoutRenderers/AspNetRequestDurationLayoutRenderer.cs
+++ b/src/Shared/LayoutRenderers/AspNetRequestDurationLayoutRenderer.cs
@@ -97,7 +97,7 @@ private void RenderDurationMs(StringBuilder builder, double durationMs)
             if (ReferenceEquals(Culture, CultureInfo.InvariantCulture))
             {
                 var truncateMs = (long)durationMs;
-                if (DurationMsFormat != null && truncateMs >= 0 && truncateMs <= DurationMsFormat.Length)
+                if (DurationMsFormat != null && truncateMs >= 0 && truncateMs < DurationMsFormat.Length)
                 {
                     builder.Append(DurationMsFormat[truncateMs]);
                 }
@@ -114,7 +114,7 @@ private void RenderDurationMs(StringBuilder builder, double durationMs)
                     if (preciseMs < 10)
                         builder.Append('0');
 
-                    if (DurationMsFormat != null && preciseMs <= DurationMsFormat.Length)
+                    if (DurationMsFormat != null && preciseMs < DurationMsFormat.Length)
                     {
                         builder.Append(DurationMsFormat[preciseMs]);
                     }