diff --git a/datafusion/proto/proto/datafusion.proto b/datafusion/proto/proto/datafusion.proto
index bd8053c817e7..76fe449d2fa3 100644
--- a/datafusion/proto/proto/datafusion.proto
+++ b/datafusion/proto/proto/datafusion.proto
@@ -409,7 +409,7 @@ message LogicalExprNode {
 }
 
 message Wildcard {
-  optional string qualifier = 1;
+  string qualifier = 1;
 }
 
 message PlaceholderNode {
diff --git a/datafusion/proto/src/generated/pbjson.rs b/datafusion/proto/src/generated/pbjson.rs
index 88310be0318a..0671757ad427 100644
--- a/datafusion/proto/src/generated/pbjson.rs
+++ b/datafusion/proto/src/generated/pbjson.rs
@@ -25797,12 +25797,12 @@ impl serde::Serialize for Wildcard {
     {
         use serde::ser::SerializeStruct;
         let mut len = 0;
-        if self.qualifier.is_some() {
+        if !self.qualifier.is_empty() {
             len += 1;
         }
         let mut struct_ser = serializer.serialize_struct("datafusion.Wildcard", len)?;
-        if let Some(v) = self.qualifier.as_ref() {
-            struct_ser.serialize_field("qualifier", v)?;
+        if !self.qualifier.is_empty() {
+            struct_ser.serialize_field("qualifier", &self.qualifier)?;
         }
         struct_ser.end()
     }
@@ -25868,12 +25868,12 @@ impl<'de> serde::Deserialize<'de> for Wildcard {
                             if qualifier__.is_some() {
                                 return Err(serde::de::Error::duplicate_field("qualifier"));
                             }
-                            qualifier__ = map_.next_value()?;
+                            qualifier__ = Some(map_.next_value()?);
                         }
                     }
                 }
                 Ok(Wildcard {
-                    qualifier: qualifier__,
+                    qualifier: qualifier__.unwrap_or_default(),
                 })
             }
         }
diff --git a/datafusion/proto/src/generated/prost.rs b/datafusion/proto/src/generated/prost.rs
index 3dfd3938615f..771bd715d3c5 100644
--- a/datafusion/proto/src/generated/prost.rs
+++ b/datafusion/proto/src/generated/prost.rs
@@ -636,8 +636,8 @@ pub mod logical_expr_node {
 #[allow(clippy::derive_partial_eq_without_eq)]
 #[derive(Clone, PartialEq, ::prost::Message)]
 pub struct Wildcard {
-    #[prost(string, optional, tag = "1")]
-    pub qualifier: ::core::option::Option<::prost::alloc::string::String>,
+    #[prost(string, tag = "1")]
+    pub qualifier: ::prost::alloc::string::String,
 }
 #[allow(clippy::derive_partial_eq_without_eq)]
 #[derive(Clone, PartialEq, ::prost::Message)]
diff --git a/datafusion/proto/src/logical_plan/from_proto.rs b/datafusion/proto/src/logical_plan/from_proto.rs
index 193e0947d6d9..854bfda9a861 100644
--- a/datafusion/proto/src/logical_plan/from_proto.rs
+++ b/datafusion/proto/src/logical_plan/from_proto.rs
@@ -1338,7 +1338,11 @@ pub fn parse_expr(
             in_list.negated,
         ))),
         ExprType::Wildcard(protobuf::Wildcard { qualifier }) => Ok(Expr::Wildcard {
-            qualifier: qualifier.clone(),
+            qualifier: if qualifier.is_empty() {
+                None
+            } else {
+                Some(qualifier.clone())
+            },
         }),
         ExprType::ScalarFunction(expr) => {
             let scalar_function = protobuf::ScalarFunction::try_from(expr.fun)
diff --git a/datafusion/proto/src/logical_plan/to_proto.rs b/datafusion/proto/src/logical_plan/to_proto.rs
index 2997d147424d..b9987ff6c727 100644
--- a/datafusion/proto/src/logical_plan/to_proto.rs
+++ b/datafusion/proto/src/logical_plan/to_proto.rs
@@ -1000,7 +1000,7 @@ impl TryFrom<&Expr> for protobuf::LogicalExprNode {
             }
             Expr::Wildcard { qualifier } => Self {
                 expr_type: Some(ExprType::Wildcard(protobuf::Wildcard {
-                    qualifier: qualifier.clone(),
+                    qualifier: qualifier.clone().unwrap_or("".to_string()),
                 })),
             },
             Expr::ScalarSubquery(_)