diff --git a/libraries/classes/Advisor.php b/libraries/classes/Advisor.php
index ea6bd95465..99bf7d4beb 100644
--- a/libraries/classes/Advisor.php
+++ b/libraries/classes/Advisor.php
@@ -396,7 +396,22 @@ class Advisor
      */
     private function evaluateRuleExpression(string $expression)
     {
-        return $this->expression->evaluate($expression, array_merge($this->variables, $this->globals));
+        $variables = array_merge($this->variables, $this->globals);
+
+        // Set default values for missing InnoDB variables when InnoDB is disabled
+        if (! isset($variables['innodb_buffer_pool_size'])) {
+            $variables['innodb_buffer_pool_size'] = 0;
+        }
+
+        if (! isset($variables['innodb_log_file_size'])) {
+            $variables['innodb_log_file_size'] = 0;
+        }
+
+        if (! isset($variables['innodb_log_files_in_group'])) {
+            $variables['innodb_log_files_in_group'] = 0;
+        }
+        
+        return $this->expression->evaluate($expression, $variables);
     }
 
     /**