diff --git a/src/EFCore.PG/Storage/Internal/Mapping/NpgsqlIntervalTypeMapping.cs b/src/EFCore.PG/Storage/Internal/Mapping/NpgsqlIntervalTypeMapping.cs
index 7bf603944..1b43e609c 100644
--- a/src/EFCore.PG/Storage/Internal/Mapping/NpgsqlIntervalTypeMapping.cs
+++ b/src/EFCore.PG/Storage/Internal/Mapping/NpgsqlIntervalTypeMapping.cs
@@ -90,9 +90,15 @@ protected override string GenerateEmbeddedNonNullSqlLiteral(object value)
     ///     doing so can result in application failures when updating to a new Entity Framework Core release.
     /// </summary>
     public static string FormatTimeSpanAsInterval(TimeSpan ts)
-        => ts.ToString(
+    {
+        // PostgreSQL intervals have microsecond precision, but TimeSpan has 100ns tick precision. Truncate the sub-microsecond part,
+        // otherwise a value with only sub-microsecond ticks gets formatted with a trailing decimal separator (e.g. 00:23:00.).
+        ts = new TimeSpan(ts.Ticks - ts.Ticks % TimeSpan.TicksPerMicrosecond);
+
+        return ts.ToString(
             $@"{(ts < TimeSpan.Zero ? "\\-" : "")}{(ts.Days == 0 ? "" : "d\\ ")}hh\:mm\:ss{(ts.Ticks % 10000000 == 0 ? "" : "\\.FFFFFF")}",
             CultureInfo.InvariantCulture);
+    }
 
     /// <summary>
     ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
diff --git a/test/EFCore.PG.Tests/Storage/NpgsqlTypeMappingTest.cs b/test/EFCore.PG.Tests/Storage/NpgsqlTypeMappingTest.cs
index bfefb835a..3c29ffc28 100644
--- a/test/EFCore.PG.Tests/Storage/NpgsqlTypeMappingTest.cs
+++ b/test/EFCore.PG.Tests/Storage/NpgsqlTypeMappingTest.cs
@@ -1,8 +1,10 @@
 using System.Collections;
 using System.Collections.Immutable;
+using System.Globalization;
 using System.Net;
 using System.Net.NetworkInformation;
 using System.Numerics;
+using System.Text;
 using System.Text.Json;
 using Microsoft.EntityFrameworkCore.Design.Internal;
 using Microsoft.EntityFrameworkCore.Storage.Json;
@@ -245,6 +247,35 @@ public void GenerateSqlLiteral_returns_interval_literal()
         Assert.Equal("INTERVAL '3 04:05:06'", mapping.GenerateSqlLiteral(new TimeSpan(3, 4, 5, 6)));
         Assert.Equal("INTERVAL '04:05:06'", mapping.GenerateSqlLiteral(new TimeSpan(4, 5, 6)));
         Assert.Equal("INTERVAL '-3 04:05:06.007'", mapping.GenerateSqlLiteral(new TimeSpan(-3, -4, -5, -6, -7)));
+        Assert.Equal(
+            "INTERVAL '3 04:05:06'", mapping.GenerateSqlLiteral(
+                new TimeSpan(3, 4, 5, 6)
+                    .Add(TimeSpan.FromTicks(3))));
+    }
+
+    [Theory]
+    [InlineData("00:00:00", "00:00:00")]
+    [InlineData("12:23:23.801885", "12:23:23.801885")]
+    [InlineData("00:23:00.0000003", "00:23:00")]
+    [InlineData("00:00:00.0000001", "00:00:00")]
+    [InlineData("00:00:00.0000009", "00:00:00")]
+    [InlineData("00:00:00.000001", "00:00:00.000001")]
+    [InlineData("00:00:00.0000013", "00:00:00.000001")]
+    [InlineData("-00:00:00.0000001", "00:00:00")]
+    [InlineData("-00:00:00.0000009", "00:00:00")]
+    [InlineData("-00:00:00.000001", "-00:00:00.000001")]
+    public void TimeSpan_json(string timeSpanString, string json)
+    {
+        var readerWriter = GetMapping(typeof(TimeSpan)).JsonValueReaderWriter!;
+
+        var timeSpan = TimeSpan.Parse(timeSpanString, CultureInfo.InvariantCulture);
+        var actualJson = readerWriter.ToJsonString(timeSpan)[1..^1];
+        Assert.Equal(json, actualJson);
+
+        var readerManager = new Utf8JsonReaderManager(new JsonReaderData(Encoding.UTF8.GetBytes($"\"{json}\"")), null);
+        readerManager.MoveNext();
+        var actualTimeSpan = readerWriter.FromJson(ref readerManager, existingObject: null);
+        Assert.Equal(TimeSpan.Parse(json, CultureInfo.InvariantCulture), actualTimeSpan);
     }
 
     #endregion Date/Time