diff --git a/airbyte-integrations/connectors/destination-s3/src/main/java/io/airbyte/integrations/destination/s3/avro/JsonSchemaType.java b/airbyte-integrations/connectors/destination-s3/src/main/java/io/airbyte/integrations/destination/s3/avro/JsonSchemaType.java
index 68a86d3ddf1f..593957066e4d 100644
--- a/airbyte-integrations/connectors/destination-s3/src/main/java/io/airbyte/integrations/destination/s3/avro/JsonSchemaType.java
+++ b/airbyte-integrations/connectors/destination-s3/src/main/java/io/airbyte/integrations/destination/s3/avro/JsonSchemaType.java
@@ -16,6 +16,7 @@
 public enum JsonSchemaType {
 
   STRING("string", true, null, Schema.Type.STRING),
+  // We currently don't distinguish between int and long
   NUMBER_INT("number", true, "integer", Schema.Type.LONG),
   NUMBER_BIGINT("number", true, "big_integer", Schema.Type.STRING),
   NUMBER_FLOAT("number", true, "float", Schema.Type.FLOAT),
diff --git a/airbyte-integrations/connectors/destination-s3/src/main/java/io/airbyte/integrations/destination/s3/avro/JsonToAvroSchemaConverter.java b/airbyte-integrations/connectors/destination-s3/src/main/java/io/airbyte/integrations/destination/s3/avro/JsonToAvroSchemaConverter.java
index aae14dae955a..f13e954d8be3 100644
--- a/airbyte-integrations/connectors/destination-s3/src/main/java/io/airbyte/integrations/destination/s3/avro/JsonToAvroSchemaConverter.java
+++ b/airbyte-integrations/connectors/destination-s3/src/main/java/io/airbyte/integrations/destination/s3/avro/JsonToAvroSchemaConverter.java
@@ -4,6 +4,8 @@
 
 package io.airbyte.integrations.destination.s3.avro;
 
+import static java.util.Collections.singletonList;
+
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.node.ArrayNode;
 import com.google.common.base.Preconditions;
@@ -59,7 +61,7 @@ static List<JsonSchemaType> getNonNullTypes(final String fieldName, final JsonNo
   static List<JsonSchemaType> getTypes(final String fieldName, final JsonNode fieldDefinition) {
     final Optional<JsonNode> combinedRestriction = getCombinedRestriction(fieldDefinition);
     if (combinedRestriction.isPresent()) {
-      return Collections.singletonList(JsonSchemaType.COMBINED);
+      return singletonList(JsonSchemaType.COMBINED);
     }
 
     final JsonNode typeProperty = fieldDefinition.get(TYPE);
@@ -67,7 +69,7 @@ static List<JsonSchemaType> getTypes(final String fieldName, final JsonNode fiel
     final String airbyteType = airbyteTypeProperty == null ? null : airbyteTypeProperty.asText();
     if (typeProperty == null || typeProperty.isNull()) {
       LOGGER.warn("Field \"{}\" has no type specification. It will default to string", fieldName);
-      return Collections.singletonList(JsonSchemaType.STRING);
+      return singletonList(JsonSchemaType.STRING);
     }
 
     if (typeProperty.isArray()) {
@@ -77,11 +79,11 @@ static List<JsonSchemaType> getTypes(final String fieldName, final JsonNode fiel
     }
 
     if (typeProperty.isTextual()) {
-      return Collections.singletonList(JsonSchemaType.fromJsonSchemaType(typeProperty.asText(), airbyteType));
+      return singletonList(JsonSchemaType.fromJsonSchemaType(typeProperty.asText(), airbyteType));
     }
 
     LOGGER.warn("Field \"{}\" has unexpected type {}. It will default to string.", fieldName, typeProperty);
-    return Collections.singletonList(JsonSchemaType.STRING);
+    return singletonList(JsonSchemaType.STRING);
   }
 
   static Optional<JsonNode> getCombinedRestriction(final JsonNode fieldDefinition) {
@@ -255,6 +257,8 @@ Schema parseSingleType(final String fieldName,
         } else if (items.isArray()) {
           final List<Schema> arrayElementTypes =
               parseJsonTypeUnion(fieldName, fieldNamespace, (ArrayNode) items, appendExtraProps, addStringToLogicalTypes);
+          // If any of the array elements were already null, remove them so that we can reinsert it at position 0
+          arrayElementTypes.removeAll(singletonList(NULL_SCHEMA));
           arrayElementTypes.add(0, NULL_SCHEMA);
           fieldSchema = Schema.createArray(Schema.createUnion(arrayElementTypes));
         } else {
@@ -406,6 +410,11 @@ List<Schema> mergeRecordSchemas(final String fieldName,
       mergedSchemas.add(assembler.endRecord());
     }
 
+    // If the schema is nullable, make sure that it's the first item in the list
+    if (mergedSchemas.removeAll(singletonList(NULL_SCHEMA))) {
+      mergedSchemas.add(0, NULL_SCHEMA);
+    }
+
     return mergedSchemas;
   }
 
diff --git a/airbyte-integrations/connectors/destination-s3/src/test/resources/parquet/json_schema_converter/type_conversion_test_cases.json b/airbyte-integrations/connectors/destination-s3/src/test/resources/parquet/json_schema_converter/type_conversion_test_cases.json
index 2262b4ff76e6..071bc98b0bbb 100644
--- a/airbyte-integrations/connectors/destination-s3/src/test/resources/parquet/json_schema_converter/type_conversion_test_cases.json
+++ b/airbyte-integrations/connectors/destination-s3/src/test/resources/parquet/json_schema_converter/type_conversion_test_cases.json
@@ -12,7 +12,7 @@
       "type": "number",
       "airbyte_type": "integer"
     },
-    "avroFieldType": ["null", "int"]
+    "avroFieldType": ["null", "long"]
   },
   {
     "fieldName": "big_integer_field",
@@ -20,7 +20,7 @@
       "type": "number",
       "airbyte_type": "big_integer"
     },
-    "avroFieldType": ["null", "long"]
+    "avroFieldType": ["null", "string"]
   },
   {
     "fieldName": "float_field",
@@ -81,7 +81,7 @@
       "null",
       {
         "type": "array",
-        "items": ["null", "string", "double", "long"]
+        "items": ["null", "string", "double"]
       }
     ]
   },
@@ -115,7 +115,7 @@
           },
           {
             "name": "long_id",
-            "type": ["null", "long"],
+            "type": ["null", "string"],
             "default": null
           },
           {
@@ -197,7 +197,7 @@
         { "type": "number", "airbyte_type": "big_integer" }
       ]
     },
-    "avroFieldType": ["null", "string", "int", "long"]
+    "avroFieldType": ["null", "string", "int"]
   },
   {
     "fieldName": "logical_type_date_time",