diff --git a/src/libraries/System.Private.CoreLib/src/System/Threading/PeriodicTimer.cs b/src/libraries/System.Private.CoreLib/src/System/Threading/PeriodicTimer.cs
index b16c4d067b7ed7df2bd0825544122ff1a789ee51..9223873e6272daba0bbd2caa8d0cb0041b0c56d1 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Threading/PeriodicTimer.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Threading/PeriodicTimer.cs
@@ -23,7 +23,7 @@ public sealed class PeriodicTimer : IDisposable
 
         /// <summary>Initializes the timer.</summary>
         /// <param name="period">The time interval between invocations of callback..</param>
-        /// <exception cref="ArgumentOutOfRangeException"><paramref name="period"/> must be represent a number of milliseconds larger than 0 and smaller than <see cref="uint.MaxValue"/>.</exception>
+        /// <exception cref="ArgumentOutOfRangeException"><paramref name="period"/> must represent a number of milliseconds equal to or larger than 1, and smaller than <see cref="uint.MaxValue"/>.</exception>
         public PeriodicTimer(TimeSpan period)
         {
             long ms = (long)period.TotalMilliseconds;