diff --git a/datafusion/src/plugin/udf.rs b/datafusion/src/plugin/udf.rs
index 7f223ee69570..0c61fc2b35b9 100644
--- a/datafusion/src/plugin/udf.rs
+++ b/datafusion/src/plugin/udf.rs
@@ -70,7 +70,9 @@ impl PluginRegistrar for UDFPluginManager {
             .unwrap()
             .iter()
             .try_for_each(|udf_name| {
+                println!("udf_name: {}", udf_name);
                 if self.scalar_udfs.contains_key(udf_name) {
+                    println!("udf_name exists");
                     Err(DataFusionError::IoError(io::Error::new(
                         io::ErrorKind::Other,
                         format!("udf name: {} already exists", udf_name),
@@ -88,7 +90,9 @@ impl PluginRegistrar for UDFPluginManager {
             .unwrap()
             .iter()
             .try_for_each(|udaf_name| {
+                println!("udaf_name: {}", udaf_name);
                 if self.aggregate_udfs.contains_key(udaf_name) {
+                    println!("udaf_name exists");
                     Err(DataFusionError::IoError(io::Error::new(
                         io::ErrorKind::Other,
                         format!("udaf name: {} already exists", udaf_name),