diff --git a/geom/webviewer/src/RGeomData.cxx b/geom/webviewer/src/RGeomData.cxx
index e478ceb73be54586c1e40cc790a96c1531d92392..49f6b0a8372c197d9f7daa7d94c1ae00f2793efa 100644
--- a/geom/webviewer/src/RGeomData.cxx
+++ b/geom/webviewer/src/RGeomData.cxx
@@ -44,6 +44,7 @@
 #include "TRegexp.h"
 
 #include <algorithm>
+#include <array>
 
 namespace ROOT {
 namespace Experimental {