diff --git a/src/csharp/Grpc.Core.Tests/TimespecTest.cs b/src/csharp/Grpc.Core.Tests/TimespecTest.cs
index f5bae6d93552c670bf4f919dd654d2c2eecd480d..5831121add39f69e30eb5dd41da3e046beeee003 100644
--- a/src/csharp/Grpc.Core.Tests/TimespecTest.cs
+++ b/src/csharp/Grpc.Core.Tests/TimespecTest.cs
@@ -61,28 +61,28 @@ namespace Grpc.Core.Internal.Tests
         [Test]
         public void Add()
         {
-            var t = new Timespec { tv_sec = new IntPtr(12345), tv_nsec = new IntPtr(123456789) };
+            var t = new Timespec { tv_sec = new IntPtr(12345), tv_nsec = 123456789 };
             var result = t.Add(TimeSpan.FromTicks(TimeSpan.TicksPerSecond * 10));
             Assert.AreEqual(result.tv_sec, new IntPtr(12355));
-            Assert.AreEqual(result.tv_nsec, new IntPtr(123456789));
+            Assert.AreEqual(result.tv_nsec, 123456789);
         }
 
         [Test]
         public void Add_Nanos()
         {
-            var t = new Timespec { tv_sec = new IntPtr(12345), tv_nsec = new IntPtr(123456789) };
+            var t = new Timespec { tv_sec = new IntPtr(12345), tv_nsec = 123456789 };
             var result = t.Add(TimeSpan.FromTicks(10));
             Assert.AreEqual(result.tv_sec, new IntPtr(12345));
-            Assert.AreEqual(result.tv_nsec, new IntPtr(123456789 + 1000));
+            Assert.AreEqual(result.tv_nsec, 123456789 + 1000);
         }
 
         [Test]
         public void Add_NanosOverflow()
         {
-            var t = new Timespec { tv_sec = new IntPtr(12345), tv_nsec = new IntPtr(999999999) };
+            var t = new Timespec { tv_sec = new IntPtr(12345), tv_nsec = 999999999 };
             var result = t.Add(TimeSpan.FromTicks(TimeSpan.TicksPerSecond * 10 + 10));
             Assert.AreEqual(result.tv_sec, new IntPtr(12356));
-            Assert.AreEqual(result.tv_nsec, new IntPtr(999));
+            Assert.AreEqual(result.tv_nsec, 999);
         }
     }
 }
diff --git a/src/csharp/Grpc.Core/Internal/Enums.cs b/src/csharp/Grpc.Core/Internal/Enums.cs
index af11b5b9f3c5f570dbe44679dcf308604958f07c..185098160b6e5d065ec4fec14cca9ae68c12d726 100644
--- a/src/csharp/Grpc.Core/Internal/Enums.cs
+++ b/src/csharp/Grpc.Core/Internal/Enums.cs
@@ -90,4 +90,19 @@ namespace Grpc.Core.Internal
         /* operation completion */
         OpComplete
     }
+
+    /// <summary>
+    /// gpr_clock_type from grpc/support/time.h
+    /// </summary>
+    internal enum GPRClockType
+    {
+        /* Monotonic clock */
+        Monotonic,
+
+        /* Realtime clock */
+        Realtime,
+
+        /* Timespan - the distance between two time points */
+        Timespan
+    }
 }
diff --git a/src/csharp/Grpc.Core/Internal/Timespec.cs b/src/csharp/Grpc.Core/Internal/Timespec.cs
index 775af27db90a19fec62b6d47e9985a4745eae61f..de783f5a4bcfe0d1e6252f6501fe5f4b339a2cb4 100644
--- a/src/csharp/Grpc.Core/Internal/Timespec.cs
+++ b/src/csharp/Grpc.Core/Internal/Timespec.cs
@@ -55,7 +55,8 @@ namespace Grpc.Core.Internal
         // NOTE: on linux 64bit  sizeof(gpr_timespec) = 16, on windows 32bit sizeof(gpr_timespec) = 8
         // so IntPtr seems to have the right size to work on both.
         public System.IntPtr tv_sec;
-        public System.IntPtr tv_nsec;
+        public int tv_nsec;
+        public GPRClockType clock_type;
 
         /// <summary>
         /// Timespec a long time in the future.
@@ -99,12 +100,13 @@ namespace Grpc.Core.Internal
 
         public Timespec Add(TimeSpan timeSpan)
         {
-            long nanos = tv_nsec.ToInt64() + (timeSpan.Ticks % TimeSpan.TicksPerSecond) * NanosPerTick;
+            long nanos = (long)tv_nsec + (timeSpan.Ticks % TimeSpan.TicksPerSecond) * NanosPerTick;
             long overflow_sec = (nanos > NanosPerSecond) ? 1 : 0;
 
             Timespec result;
-            result.tv_nsec = new IntPtr(nanos % NanosPerSecond);
+            result.tv_nsec = (int)(nanos % NanosPerSecond);
             result.tv_sec = new IntPtr(tv_sec.ToInt64() + (timeSpan.Ticks / TimeSpan.TicksPerSecond) + overflow_sec);
+            result.clock_type = GPRClockType.Realtime;
             return result;
         }
     }