diff --git a/reference_option_limit.module b/reference_option_limit.module
index 800e2ae..0e4d33c 100644
--- a/reference_option_limit.module
+++ b/reference_option_limit.module
@@ -303,7 +303,7 @@ function reference_option_limit_form_alter(&$form, &$form_state, $form_id) {
         // Build an array of field values to match on. This is keyed first by
         // field name, and then by delta (or with default values, whatever).
         // First time around these are in default values; in ajax calls these are in $form_state.
-        if (isset($form_state['values'])) {
+        if (isset($form_state['values'][$field_name_matching])) {
           // @todo: Figure out what on earth should happen when we have more than one column!
           $column = $match_columns[$field_name_matching][0];
           foreach ($form_state['values'][$field_name_matching][LANGUAGE_NONE] as $delta => $item) {