diff --git a/extension/qfq/qfq/AbstractBuildForm.php b/extension/qfq/qfq/AbstractBuildForm.php
index acd4174fcbe9d7a5c7a331ac2152937f44991be8..7d527d2e4d962c08c0996b03ac63e99e8c42612b 100644
--- a/extension/qfq/qfq/AbstractBuildForm.php
+++ b/extension/qfq/qfq/AbstractBuildForm.php
@@ -1265,14 +1265,16 @@ abstract class AbstractBuildForm {
 
         $sql = trim($sql);
 
-        if ($sql[0] = '[') {
+        if ($sql[0] == '[') {
             // Remove optional existing dbIndex token.
             $pos = strpos($sql, ']');
             $sqlTest = substr($sql, $pos + 1);
+        } else {
+            $sqlTest = $sql;
         }
 
         if (false === stristr(substr($sqlTest, 0, 7), 'SELECT ')) {
-            throw new UserFormException("Expect a SELECT statement in " . FE_TYPEAHEAD_SQL . " - got: " . $sql, ERROR_BROKEN_PARAMETER);
+            throw new UserFormException("Expect a SELECT statement in " . FE_TYPEAHEAD_SQL . " - got: " . $sqlTest, ERROR_BROKEN_PARAMETER);
         }
 
         if (false === stristr($sql, ' LIMIT ')) {