diff --git a/proxy/src/serverless/json.rs b/proxy/src/serverless/json.rs
index 2e67d07079..0e0a8c1a08 100644
--- a/proxy/src/serverless/json.rs
+++ b/proxy/src/serverless/json.rs
@@ -22,7 +22,7 @@ fn json_value_to_pg_text(value: &Value) -> Option<String> {
         Value::String(s) => Some(s.clone()),
 
         // special care for arrays
-        Value::Array(_) => json_array_to_pg_array(value),
+        Value::Array(arr) => Some(json_array_to_pg_array(arr)),
     }
 }
 
@@ -34,28 +34,29 @@ fn json_value_to_pg_text(value: &Value) -> Option<String> {
 //
 // Example of the same escaping in node-postgres: packages/pg/lib/utils.js
 //
-fn json_array_to_pg_array(value: &Value) -> Option<String> {
-    match value {
-        // special care for nulls
-        Value::Null => None,
-
-        // convert to text with escaping
-        // here string needs to be escaped, as it is part of the array
-        v @ (Value::Bool(_) | Value::Number(_) | Value::String(_)) => Some(v.to_string()),
-        v @ Value::Object(_) => json_array_to_pg_array(&Value::String(v.to_string())),
-
-        // recurse into array
-        Value::Array(arr) => {
-            let vals = arr
-                .iter()
-                .map(json_array_to_pg_array)
-                .map(|v| v.unwrap_or_else(|| "NULL".to_string()))
-                .collect::<Vec<_>>()
-                .join(",");
-
-            Some(format!("{{{vals}}}"))
+fn json_array_to_pg_array(arr: &[Value]) -> String {
+    let mut output = String::new();
+    output.push('{');
+    for val in arr {
+        if output.len() > 1 {
+            output.push(',');
         }
+
+        let val = match val {
+            Value::Null => "NULL".to_string(),
+
+            // convert to text with escaping
+            // here string needs to be escaped, as it is part of the array
+            v @ (Value::Bool(_) | Value::Number(_) | Value::String(_)) => v.to_string(),
+            v @ Value::Object(_) => Value::String(v.to_string()).to_string(),
+
+            // recurse into array
+            Value::Array(arr) => json_array_to_pg_array(arr),
+        };
+        output.push_str(&val);
     }
+    output.push('}');
+    output
 }
 
 #[derive(Debug, thiserror::Error)]