diff --git a/src/libraries/System.Diagnostics.Process/tests/ProcessTests.Unix.cs b/src/libraries/System.Diagnostics.Process/tests/ProcessTests.Unix.cs
index a02cc15c3a6626..832772b27a101f 100644
--- a/src/libraries/System.Diagnostics.Process/tests/ProcessTests.Unix.cs
+++ b/src/libraries/System.Diagnostics.Process/tests/ProcessTests.Unix.cs
@@ -878,9 +878,11 @@ public unsafe void TestTotalProcessorTimeMacOs()
 
             void AssertTime(TimeSpan managed, TimeSpan native, string label)
             {
+                const double ToleranceInMicroseconds = 20;
+                double differenceUs = (managed - native).TotalMicroseconds;
                 Assert.True(
-                    managed >= native,
-                    $"Time '{label}' returned by managed API ({managed}) should be greated or equal to the time returned by native API ({native}).");
+                    differenceUs >= -ToleranceInMicroseconds,
+                    $"Time '{label}' returned by managed API ({managed}) should be greater or equal to the time returned by native API ({native}) within a tolerance of {ToleranceInMicroseconds} μs.");
             }
         }