diff --git a/lang/csharp/src/apache/test/AvroGen/AvroGenTests.cs b/lang/csharp/src/apache/test/AvroGen/AvroGenTests.cs
index 2426bc27519..1f61fc547dc 100644
--- a/lang/csharp/src/apache/test/AvroGen/AvroGenTests.cs
+++ b/lang/csharp/src/apache/test/AvroGen/AvroGenTests.cs
@@ -161,8 +161,11 @@ class AvroGenTests
       ""type"": [""null"", {
         ""namespace"": ""org.apache.avro.codegentest.testdata"",
         ""name"": ""FixedInUnion"",
-        ""type"": ""fixed"",
-        ""size"": 12,
+        ""type"": {
+            ""type"": ""fixed"",
+            ""size"": 12,
+            ""name"": ""FixedName"",
+        },
         ""logicalType"": ""decimal"",
         ""precision"": 28,
         ""scale"": 15
@@ -442,6 +445,16 @@ private Assembly TestSchema(
                 "org/apache/avro/codegentest/some/NestedSomeNamespaceRecord.cs",
                 "org/apache/avro/codegentest/other/NestedOtherNamespaceRecord.cs"
             })]
+        [TestCase(
+            _nestedLogicalTypesUnionFixedDecimal,
+            new string[]
+            {
+                "org.apache.avro.codegentest.testdata.NestedLogicalTypesUnionFixedDecimal"
+            },
+            new string[]
+            {
+                "org/apache/avro/codegentest/testdata/NestedLogicalTypesUnionFixedDecimal.cs"
+            })]
         [TestCase(
             _nullableLogicalTypes,
             new string[]
@@ -595,7 +608,6 @@ public void GenerateSchemaWithNamespaceMapping(
 
         [TestCase(_logicalTypesWithCustomConversion, typeof(AvroTypeException))]
         [TestCase(_customConversionWithLogicalTypes, typeof(SchemaParseException))]
-        [TestCase(_nestedLogicalTypesUnionFixedDecimal, typeof(SchemaParseException))]
         public void NotSupportedSchema(string schema, Type expectedException)
         {
             // Create temp folder
@@ -670,26 +682,28 @@ public void NotSupportedSchema(string schema, Type expectedException)
             new object[] { "schematest.SchemaObject", typeof(IList<object>) })]
         [TestCase(@"
 {
-	""type"" : ""record"",
-	""name"" : ""LogicalTypes"",
-	""namespace"" : ""schematest"",
-	""fields"" :
-		[
-			{ ""name"" : ""nullibleguid"", ""type"" : [""null"", {""type"": ""string"", ""logicalType"": ""uuid"" } ]},
-			{ ""name"" : ""guid"", ""type"" : {""type"": ""string"", ""logicalType"": ""uuid"" } },
-			{ ""name"" : ""nullibletimestampmillis"", ""type"" : [""null"", {""type"": ""long"", ""logicalType"": ""timestamp-millis""}]  },
-			{ ""name"" : ""timestampmillis"", ""type"" : {""type"": ""long"", ""logicalType"": ""timestamp-millis""} },
-			{ ""name"" : ""nullibiletimestampmicros"", ""type"" : [""null"", {""type"": ""long"", ""logicalType"": ""timestamp-micros""}]  },
-			{ ""name"" : ""timestampmicros"", ""type"" : {""type"": ""long"", ""logicalType"": ""timestamp-micros""} },
-			{ ""name"" : ""nullibiletimemicros"", ""type"" : [""null"", {""type"": ""long"", ""logicalType"": ""time-micros""}]  },
-			{ ""name"" : ""timemicros"", ""type"" : {""type"": ""long"", ""logicalType"": ""time-micros""} },
-			{ ""name"" : ""nullibiletimemillis"", ""type"" : [""null"", {""type"": ""int"", ""logicalType"": ""time-millis""}]  },
-			{ ""name"" : ""timemillis"", ""type"" : {""type"": ""int"", ""logicalType"": ""time-millis""} },
-			{ ""name"" : ""nullibledecimal"", ""type"" : [""null"", {""type"": ""bytes"", ""logicalType"": ""decimal"", ""precision"": 4, ""scale"": 2}]  },
-            { ""name"" : ""decimal"", ""type"" : {""type"": ""bytes"", ""logicalType"": ""decimal"", ""precision"": 4, ""scale"": 2} }
-		]
+  ""type"" : ""record"",
+  ""name"" : ""LogicalTypes"",
+  ""namespace"" : ""schematest"",
+  ""fields"" :
+    [
+      { ""name"" : ""nullibleguid"", ""type"" : [""null"", {""type"": ""string"", ""logicalType"": ""uuid"" } ]},
+      { ""name"" : ""guid"", ""type"" : {""type"": ""string"", ""logicalType"": ""uuid"" } },
+      { ""name"" : ""nullibletimestampmillis"", ""type"" : [""null"", {""type"": ""long"", ""logicalType"": ""timestamp-millis""}]  },
+      { ""name"" : ""timestampmillis"", ""type"" : {""type"": ""long"", ""logicalType"": ""timestamp-millis""} },
+      { ""name"" : ""nullibiletimestampmicros"", ""type"" : [""null"", {""type"": ""long"", ""logicalType"": ""timestamp-micros""}]  },
+      { ""name"" : ""timestampmicros"", ""type"" : {""type"": ""long"", ""logicalType"": ""timestamp-micros""} },
+      { ""name"" : ""nullibiletimemicros"", ""type"" : [""null"", {""type"": ""long"", ""logicalType"": ""time-micros""}]  },
+      { ""name"" : ""timemicros"", ""type"" : {""type"": ""long"", ""logicalType"": ""time-micros""} },
+      { ""name"" : ""nullibiletimemillis"", ""type"" : [""null"", {""type"": ""int"", ""logicalType"": ""time-millis""}]  },
+      { ""name"" : ""timemillis"", ""type"" : {""type"": ""int"", ""logicalType"": ""time-millis""} },
+      { ""name"" : ""nullibledecimal"", ""type"" : [""null"", {""type"": ""bytes"", ""logicalType"": ""decimal"", ""precision"": 4, ""scale"": 2}]  },
+      { ""name"" : ""decimal"", ""type"" : {""type"": ""bytes"", ""logicalType"": ""decimal"", ""precision"": 4, ""scale"": 2} },
+      { ""name"" : ""nullibledecimalfixed"", ""type"" : [""null"", {""type"": {""type"" : ""fixed"", ""size"": 16, ""name"": ""ndf""}, ""logicalType"": ""decimal"", ""precision"": 4, ""scale"": 2}]  },
+      { ""name"" : ""decimalfixed"", ""type"" : {""type"": {""type"" : ""fixed"", ""size"": 16, ""name"": ""df""}, ""logicalType"": ""decimal"", ""precision"": 4, ""scale"": 2} }
+    ]
 }",
-            new object[] { "schematest.LogicalTypes", typeof(Guid?), typeof(Guid), typeof(DateTime?), typeof(DateTime), typeof(DateTime?), typeof(DateTime), typeof(TimeSpan?), typeof(TimeSpan), typeof(TimeSpan?), typeof(TimeSpan), typeof(AvroDecimal?), typeof(AvroDecimal) })]
+            new object[] { "schematest.LogicalTypes", typeof(Guid?), typeof(Guid), typeof(DateTime?), typeof(DateTime), typeof(DateTime?), typeof(DateTime), typeof(TimeSpan?), typeof(TimeSpan), typeof(TimeSpan?), typeof(TimeSpan), typeof(AvroDecimal?), typeof(AvroDecimal), typeof(AvroDecimal?), typeof(AvroDecimal) })]
         [TestCase(@"
 {
   ""namespace"": ""enum.base"",
diff --git a/lang/csharp/src/apache/test/Util/LogicalTypeTests.cs b/lang/csharp/src/apache/test/Util/LogicalTypeTests.cs
index 9630b7c6716..0b89c7d17db 100644
--- a/lang/csharp/src/apache/test/Util/LogicalTypeTests.cs
+++ b/lang/csharp/src/apache/test/Util/LogicalTypeTests.cs
@@ -58,15 +58,22 @@ public void TestDecimalConvert(string s, int scale, byte[] converted)
             Assert.AreEqual(decimalVal, (AvroDecimal)avroDecimal.ConvertToLogicalValue(converted, schema));
         }
 
-        [TestCase("1234.56")]
-        [TestCase("-1234.56")]
-        [TestCase("123456789123456789.56")]
-        [TestCase("-123456789123456789.56")]
-        [TestCase("000000000000000001.01")]
-        [TestCase("-000000000000000001.01")]
-        public void TestDecimal(string s)
+        [Test]
+        public void TestDecimal(
+            [Values(
+                "1234.56",
+                "-1234.56",
+                "123456789123456789.56",
+                "-123456789123456789.56",
+                "000000000000000001.01",
+                "-000000000000000001.01"
+            )] string s, 
+            [Values(
+                "\"bytes\"",
+                "{\"type\": \"fixed\", \"size\": 16, \"name\": \"n\"}"
+            )] string baseType)
         {
-            var schema = (LogicalSchema)Schema.Parse("{\"type\": \"bytes\", \"logicalType\": \"decimal\", \"precision\": 4, \"scale\": 2 }");
+            var schema = (LogicalSchema)Schema.Parse($"{{\"type\": {baseType}, \"logicalType\": \"decimal\", \"precision\": 4, \"scale\": 2 }}");
 
             var avroDecimal = new Avro.Util.Decimal();
             // CultureInfo.InvariantCulture ensures that "." is always accepted as the decimal point
@@ -77,10 +84,38 @@ public void TestDecimal(string s)
             Assert.AreEqual(decimalVal, convertedDecimalVal);
         }
 
-        [TestCase]
-        public void TestDecimalMinMax()
+        [Test]
+        public void TestDecimalScale(
+            [Values(
+                "0",
+                "1",
+                "-1",
+                "1234567891234567890123456789",
+                "-1234567891234567890123456789",
+                "0000000000000000000000000001",
+                "-0000000000000000000000000001"
+            )] string s, 
+            [Values(1, 2, 3, 4, 5, 6, 7, 8)] int scale,
+            [Values(
+                "\"bytes\"",
+                "{\"type\": \"fixed\", \"size\": 16, \"name\": \"n\"}"
+            )] string baseType)
         {
-            var schema = (LogicalSchema)Schema.Parse("{\"type\": \"bytes\", \"logicalType\": \"decimal\", \"precision\": 4, \"scale\": 0 }");
+            var schema = (LogicalSchema)Schema.Parse($"{{\"type\": {baseType}, \"logicalType\": \"decimal\", \"precision\": 8, \"scale\": {scale} }}");
+
+            var avroDecimal = new Avro.Util.Decimal();
+            var decimalVal = new AvroDecimal(BigInteger.Parse(s), scale);
+
+            var convertedDecimalVal = (AvroDecimal)avroDecimal.ConvertToLogicalValue(avroDecimal.ConvertToBaseValue(decimalVal, schema), schema);
+
+            Assert.AreEqual(decimalVal, convertedDecimalVal);
+        }
+
+        [TestCase("\"bytes\"")]
+        [TestCase("{\"type\": \"fixed\", \"size\": 16, \"name\": \"n\"}")]
+        public void TestDecimalMinMax(string baseType)
+        {
+            var schema = (LogicalSchema)Schema.Parse($"{{\"type\": {baseType}, \"logicalType\": \"decimal\", \"precision\": 4, \"scale\": 0 }}");
 
             var avroDecimal = new Avro.Util.Decimal();
 
@@ -92,10 +127,11 @@ public void TestDecimalMinMax()
             }
         }
 
-        [TestCase]
-        public void TestDecimalOutOfRangeException()
+        [TestCase("\"bytes\"")]
+        [TestCase("{\"type\": \"fixed\", \"size\": 16, \"name\": \"n\"}")]
+        public void TestDecimalOutOfRangeException(string baseType)
         {
-            var schema = (LogicalSchema)Schema.Parse("{\"type\": \"bytes\", \"logicalType\": \"decimal\", \"precision\": 4, \"scale\": 2 }");
+            var schema = (LogicalSchema)Schema.Parse($"{{\"type\": {baseType}, \"logicalType\": \"decimal\", \"precision\": 4, \"scale\": 2 }}");
 
             var avroDecimal = new Avro.Util.Decimal();
             var decimalVal = (AvroDecimal)1234.567M; // scale of 3 should throw ArgumentOutOfRangeException