diff --git a/datafusion/core/src/test_util.rs b/datafusion/core/src/test_util.rs
index 03adc33fbfd66..a60f318a54abe 100644
--- a/datafusion/core/src/test_util.rs
+++ b/datafusion/core/src/test_util.rs
@@ -21,7 +21,6 @@ use std::any::Any;
 use std::collections::BTreeMap;
 use std::{env, error::Error, path::PathBuf, sync::Arc};
 
-use crate::datasource::custom::CustomTable;
 use crate::datasource::datasource::TableProviderFactory;
 use crate::datasource::{empty::EmptyTable, provider_as_source, TableProvider};
 use crate::execution::context::SessionState;
@@ -331,39 +330,31 @@ pub struct TestTableFactory {}
 impl TableProviderFactory for TestTableFactory {
     async fn create(
         &self,
-        _name: &str,
         url: &str,
     ) -> datafusion_common::Result<Arc<dyn TableProvider>> {
-        Ok(Arc::new(CustomTable::new(
-            "deltatable",
-            url,
-            Arc::new(TestTableProvider {}),
-        )))
+        Ok(Arc::new(TestTableProvider { url: url.to_string() }))
     }
 
     fn with_schema(
         &self,
         _schema: SchemaRef,
-        table_type: &str,
         url: &str,
     ) -> datafusion_common::Result<Arc<dyn TableProvider>> {
-        Ok(Arc::new(CustomTable::new(
-            table_type,
-            url,
-            Arc::new(TestTableProvider {}),
-        )))
+        Ok(Arc::new(TestTableProvider { url: url.to_string() }))
     }
 }
 
 /// TableProvider for testing purposes
-pub struct TestTableProvider {}
+pub struct TestTableProvider {
+    pub url: String
+}
 
 impl TestTableProvider {}
 
 #[async_trait]
 impl TableProvider for TestTableProvider {
     fn as_any(&self) -> &dyn Any {
-        unimplemented!("TestTableProvider is a stub for testing.")
+        self
     }
 
     fn schema(&self) -> SchemaRef {
diff --git a/datafusion/proto/src/lib.rs b/datafusion/proto/src/lib.rs
index 624c801730acb..92634bac436a6 100644
--- a/datafusion/proto/src/lib.rs
+++ b/datafusion/proto/src/lib.rs
@@ -51,7 +51,7 @@ mod roundtrip_tests {
         logical_plan_to_bytes, logical_plan_to_bytes_with_extension_codec,
     };
     use crate::logical_plan::LogicalExtensionCodec;
-    use arrow::datatypes::Schema;
+    use arrow::datatypes::{Schema, SchemaRef};
     use arrow::{
         array::ArrayRef,
         datatypes::{
@@ -65,7 +65,7 @@ mod roundtrip_tests {
     use datafusion::prelude::{
         create_udf, CsvReadOptions, SessionConfig, SessionContext,
     };
-    use datafusion::test_util::TestTableFactory;
+    use datafusion::test_util::{TestTableFactory, TestTableProvider};
     use datafusion_common::{DFSchemaRef, DataFusionError, ScalarValue};
     use datafusion_expr::create_udaf;
     use datafusion_expr::expr::{Between, BinaryExpr, Case, GroupingSet, Like};
@@ -81,6 +81,7 @@ mod roundtrip_tests {
     use std::fmt::Debug;
     use std::fmt::Formatter;
     use std::sync::Arc;
+    use datafusion::datasource::TableProvider;
 
     #[cfg(feature = "json")]
     fn roundtrip_json_test(proto: &protobuf::LogicalExprNode) {
@@ -135,22 +136,73 @@ mod roundtrip_tests {
         Ok(())
     }
 
+    #[derive(Clone, PartialEq, ::prost::Message)]
+    pub struct TestTableProto {
+        /// URL of the table root
+        #[prost(string, tag = "1")]
+        pub url: String,
+    }
+
+    #[derive(Debug)]
+    pub struct TestTableProviderCodec {}
+
+    impl LogicalExtensionCodec for TestTableProviderCodec {
+        fn try_decode(&self, buf: &[u8], inputs: &[LogicalPlan], ctx: &SessionContext) -> Result<Extension, DataFusionError> {
+            Err(DataFusionError::NotImplemented(
+                "No extension codec provided".to_string(),
+            ))
+        }
+
+        fn try_encode(&self, node: &Extension, buf: &mut Vec<u8>) -> Result<(), DataFusionError> {
+            Err(DataFusionError::NotImplemented(
+                "No extension codec provided".to_string(),
+            ))
+        }
+
+        fn try_decode_table_provider(&self, buf: &[u8], schema: SchemaRef, ctx: &SessionContext) -> Result<Arc<dyn TableProvider>, DataFusionError> {
+            let msg = TestTableProto::decode(buf)
+                .map_err(|_| DataFusionError::Internal("Error encoding test table".to_string()))?;
+            let state = ctx.state.read();
+            let factory = state
+                .runtime_env
+                .table_factories
+                .get("testtable")
+                .ok_or_else(|| {
+                    DataFusionError::Plan(format!(
+                        "Unable to find testtable factory",
+                    ))
+                })?;
+            let provider = (*factory).with_schema(schema, msg.url.as_str())?;
+            Ok(provider)
+        }
+
+        fn try_encode_table_provider(&self, node: Arc<dyn TableProvider>, buf: &mut Vec<u8>) -> Result<(), DataFusionError> {
+            let table = node.as_ref().as_any().downcast_ref::<TestTableProvider>()
+                .ok_or(DataFusionError::Internal("Can't encode non-test tables".to_string()))?;
+            let msg = TestTableProto {
+                url: table.url.clone()
+            };
+            msg.encode(buf).map_err(|_| DataFusionError::Internal("Error encoding test table".to_string()))
+        }
+    }
+
     #[tokio::test]
     async fn roundtrip_custom_tables() -> Result<(), DataFusionError> {
         let mut table_factories: HashMap<String, Arc<dyn TableProviderFactory>> =
             HashMap::new();
-        table_factories.insert("deltatable".to_string(), Arc::new(TestTableFactory {}));
+        table_factories.insert("testtable".to_string(), Arc::new(TestTableFactory {}));
         let cfg = RuntimeConfig::new().with_table_factories(table_factories);
         let env = RuntimeEnv::new(cfg).unwrap();
         let ses = SessionConfig::new();
         let ctx = SessionContext::with_config_rt(ses, Arc::new(env));
 
-        let sql = "CREATE EXTERNAL TABLE dt STORED AS DELTATABLE LOCATION 's3://bucket/schema/table';";
+        let sql = "CREATE EXTERNAL TABLE t STORED AS testtable LOCATION 's3://bucket/schema/table';";
         ctx.sql(sql).await.unwrap();
 
-        let scan = ctx.table("dt")?.to_logical_plan()?;
-        let bytes = logical_plan_to_bytes(&scan)?;
-        let logical_round_trip = logical_plan_from_bytes(&bytes, &ctx)?;
+        let codec = TestTableProviderCodec {};
+        let scan = ctx.table("t")?.to_logical_plan()?;
+        let bytes = logical_plan_to_bytes_with_extension_codec(&scan, &codec)?;
+        let logical_round_trip = logical_plan_from_bytes_with_extension_codec(&bytes, &ctx, &codec)?;
         assert_eq!(format!("{:?}", scan), format!("{:?}", logical_round_trip));
         Ok(())
     }
@@ -350,6 +402,18 @@ mod roundtrip_tests {
                 ))
             }
         }
+
+        fn try_decode_table_provider(&self, buf: &[u8], schema: SchemaRef, ctx: &SessionContext) -> Result<Arc<dyn TableProvider>, DataFusionError> {
+            Err(DataFusionError::Internal(
+                "unsupported plan type".to_string(),
+            ))
+        }
+
+        fn try_encode_table_provider(&self, node: Arc<dyn TableProvider>, buf: &mut Vec<u8>) -> Result<(), DataFusionError> {
+            Err(DataFusionError::Internal(
+                "unsupported plan type".to_string(),
+            ))
+        }
     }
 
     #[test]