diff --git a/src/openlcb/MemoryConfigClient.cxxtest b/src/openlcb/MemoryConfigClient.cxxtest
index 8d8180f33..c9e7f64a7 100644
--- a/src/openlcb/MemoryConfigClient.cxxtest
+++ b/src/openlcb/MemoryConfigClient.cxxtest
@@ -37,6 +37,8 @@
 
 #include "utils/async_datagram_test_helper.hxx"
 
+#include <array>
+
 namespace openlcb
 {