diff --git a/test/function/config/sqlite3_unsupported.cpp b/test/function/config/sqlite3_unsupported.cpp
index d5830b65d..9813a4910 100644
--- a/test/function/config/sqlite3_unsupported.cpp
+++ b/test/function/config/sqlite3_unsupported.cpp
@@ -16,6 +16,7 @@
  * limitations under the License.
  */
 
+#include <cstddef>
 #include <gtest/gtest.h>
 #include <stumpless.h>
 #include "test/helper/assert.hpp"