diff --git a/app/Http/Controllers/Api/AssetsController.php b/app/Http/Controllers/Api/AssetsController.php
index bce5354b72..e42c82841e 100644
--- a/app/Http/Controllers/Api/AssetsController.php
+++ b/app/Http/Controllers/Api/AssetsController.php
@@ -582,11 +582,6 @@ class AssetsController extends Controller
                 // Set the field value based on what was sent in the request
                 $field_val = $request->input($field->db_column, null);
 
-                //reduce "array to string conversion" exceptions - ideally we'd handle this in a form request, but this works for now
-                if(is_array($field_val)) {
-                    return response()->json(Helper::formatStandardApiResponse('error', null, 'This custom field can not be an array', 200));
-                }
-
                 // If input value is null, use custom field's default value
                 if ($field_val == null) {
                     \Log::debug('Field value for '.$field->db_column.' is null');
diff --git a/app/Models/CustomFieldset.php b/app/Models/CustomFieldset.php
index a2698d818c..a62f96d631 100644
--- a/app/Models/CustomFieldset.php
+++ b/app/Models/CustomFieldset.php
@@ -92,6 +92,8 @@ class CustomFieldset extends Model
 
             array_push($rule, $field->attributes['format']);
             $rules[$field->db_column_name()] = $rule;
+            //add not_array to rules for all fields
+            $rules[$field->db_column_name()][] = 'not_array';
         }
 
         return $rules;
diff --git a/app/Providers/ValidationServiceProvider.php b/app/Providers/ValidationServiceProvider.php
index d7a3c03778..70fa64702e 100644
--- a/app/Providers/ValidationServiceProvider.php
+++ b/app/Providers/ValidationServiceProvider.php
@@ -232,6 +232,10 @@ class ValidationServiceProvider extends ServiceProvider
                 return true;
             }
         });
+
+        Validator::extend('not_array', function ($attribute, $value, $parameters, $validator) {
+            return !is_array($value);
+        });
     }
 
     /**
diff --git a/resources/lang/en/validation.php b/resources/lang/en/validation.php
index df514da6f9..7720fda79d 100644
--- a/resources/lang/en/validation.php
+++ b/resources/lang/en/validation.php
@@ -95,6 +95,7 @@ return [
     'url'                  => 'The :attribute format is invalid.',
     'unique_undeleted'     => 'The :attribute must be unique.',
     'non_circular'         => 'The :attribute must not create a circular reference.',
+    'not_array'            => 'The :attribute field can not be an array.',
     'disallow_same_pwd_as_user_fields' => 'Password cannot be the same as the username.',
     'letters'              => 'Password must contain at least one letter.',
     'numbers'              => 'Password must contain at least one number.',