diff --git a/packages/server/src/sdk/app/rows/utils.ts b/packages/server/src/sdk/app/rows/utils.ts
index a9df4f89cd..777ebff655 100644
--- a/packages/server/src/sdk/app/rows/utils.ts
+++ b/packages/server/src/sdk/app/rows/utils.ts
@@ -14,7 +14,7 @@ import { makeExternalQuery } from "../../../integrations/base/query"
 import { Format } from "../../../api/controllers/view/exporters"
 import sdk from "../.."
 import { isRelationshipColumn } from "../../../db/utils"
-import { SqlClient, isSQL } from "../../../integrations/utils"
+import { isSQL, SqlClient } from "../../../integrations/utils"
 
 const SQL_CLIENT_SOURCE_MAP: Record<SourceName, SqlClient | undefined> = {
   [SourceName.POSTGRES]: SqlClient.POSTGRES,
@@ -144,6 +144,10 @@ export async function validate({
     throw new Error("Unable to fetch table for validation")
   }
   const errors: Record<string, any> = {}
+  const disallowArrayTypes = [
+    FieldType.ATTACHMENT_SINGLE,
+    FieldType.BB_REFERENCE_SINGLE,
+  ]
   for (let fieldName of Object.keys(fetchedTable.schema)) {
     const column = fetchedTable.schema[fieldName]
     const constraints = cloneDeep(column.constraints)
@@ -160,6 +164,10 @@ export async function validate({
     if (type === FieldType.OPTIONS && constraints?.inclusion) {
       constraints.inclusion.push(null as any, "")
     }
+
+    if (disallowArrayTypes.includes(type) && Array.isArray(row[fieldName])) {
+      errors[fieldName] = `Cannot accept arrays`
+    }
     let res
 
     // Validate.js doesn't seem to handle array