diff --git a/src/expr/src/vector_op/jsonb_concat.rs b/src/expr/src/vector_op/jsonb_concat.rs
index 1d910aa2b28a0..80e7bf7b5e5bf 100644
--- a/src/expr/src/vector_op/jsonb_concat.rs
+++ b/src/expr/src/vector_op/jsonb_concat.rs
@@ -43,19 +43,24 @@ use serde_json::{json, Value};
 /// [1, 2]
 ///
 /// query T
-/// SELECT '[1,2]'::jsonb || NULL::jsonb;
+/// SELECT '[1,2]'::jsonb || 'null'::jsonb;
 /// ----
-/// null
+/// [1, 2, null]
 ///
 /// query T
-/// SELECT NULL::jsonb || '[1,2]'::jsonb;
+/// SELECT 'null'::jsonb || '[1,2]'::jsonb;
 /// ----
-/// null
+/// [null, 1, 2]
+/// 
+/// query T
+/// SELECT 'null'::jsonb || '1'::jsonb;
+/// ----
+/// [null, 1]
 /// ```
 #[function("jsonb_cat(jsonb, jsonb) -> jsonb")]
-pub fn jsonb_cat(left: Option<JsonbRef<'_>>, right: Option<JsonbRef<'_>>) -> JsonbVal {
-    let left_val = left.map_or(Value::Null, |v| v.value().clone());
-    let right_val = right.map_or(Value::Null, |v| v.value().clone());
+pub fn jsonb_cat(left: JsonbRef<'_>, right: JsonbRef<'_>) -> JsonbVal {
+    let left_val = left.value().clone();
+    let right_val = right.value().clone();
     match (left_val, right_val) {
         // left and right are object based.
         // This would have left:{'a':1}, right:{'b':2} -> {'a':1,'b':2}
@@ -75,17 +80,18 @@ pub fn jsonb_cat(left: Option<JsonbRef<'_>>, right: Option<JsonbRef<'_>>) -> Jso
         // One operand is an array, and the other is a single element.
         // This would insert the non-array value as another element into the array
         // Eg left:[1,2] right: {'a':1} -> [1,2,{'a':1}]
-        (Value::Array(mut left_arr), single_val) | (single_val, Value::Array(mut left_arr))
-            if single_val != Value::Null =>
-        {
+        (Value::Array(mut left_arr), single_val) => {
             left_arr.push(single_val);
             JsonbVal::from(Value::Array(left_arr))
         }
 
-        // Either left/right is None
-        // This return a None value
-        // This would have left:[1,2], right:None -> None
-        (Value::Null, _) | (_, Value::Null) => JsonbVal::from(Value::Null),
+        // One operand is an array, and the other is a single element.
+        // This would insert the non-array value as another element into the array
+        // Eg left:{'a':1} right:[1,2] -> [{'a':1},1,2]
+        (single_val, Value::Array(mut right_arr)) => {
+            right_arr.insert(0,single_val);
+            JsonbVal::from(Value::Array(right_arr))
+        }
 
         // Both are non-array inputs.
         // Both elements would be placed together in an array