diff --git a/csharp/src/Google.Protobuf.Test/CodedOutputStreamTest.cs b/csharp/src/Google.Protobuf.Test/CodedOutputStreamTest.cs
index 1c77e121d3eb..1e5333c96501 100644
--- a/csharp/src/Google.Protobuf.Test/CodedOutputStreamTest.cs
+++ b/csharp/src/Google.Protobuf.Test/CodedOutputStreamTest.cs
@@ -35,6 +35,7 @@
 using Google.Protobuf.TestProtos;
 using Google.Protobuf.Buffers;
 using NUnit.Framework;
+using System.Text;
 
 namespace Google.Protobuf
 {
@@ -516,5 +517,28 @@ public void Dispose_FromByteArray()
             var stream = new CodedOutputStream(new byte[10]);
             stream.Dispose();
         }
+
+        [Test]
+        public void WriteStringsOfDifferentSizes()
+        {
+            for (int i = 1; i <= 1024; i++)
+            {
+                var buffer = new byte[4096];
+                var output = new CodedOutputStream(buffer);
+                var sb = new StringBuilder();
+                for (int j = 0; j < i; j++)
+                {
+                    sb.Append((j % 10).ToString()); // incrementing numbers, repeating
+                }
+                var s = sb.ToString();
+                output.WriteString(s);
+
+                output.Flush();
+
+                // Verify written content
+                var input = new CodedInputStream(buffer);
+                Assert.AreEqual(s, input.ReadString());
+            }
+        }
     }
 }
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