diff --git a/src/OpenFOAM/primitives/nullObject/nullObject.H b/src/OpenFOAM/primitives/nullObject/nullObject.H
index a3f2de2ef7..2b0782cb54 100644
--- a/src/OpenFOAM/primitives/nullObject/nullObject.H
+++ b/src/OpenFOAM/primitives/nullObject/nullObject.H
@@ -80,7 +80,7 @@ class NullObject
         //  Could also rely on bit-wise zero initialization for union content
         NullObject()
         :
-           data_{nullptr, nullptr, nullptr, nullptr}
+           data_{{nullptr}, {nullptr}, {nullptr}, {nullptr}}
         {}
 
         //- No copy construct