diff --git a/Source/WarpX.cpp b/Source/WarpX.cpp
index 22305ae93b6..9ec29b07f01 100644
--- a/Source/WarpX.cpp
+++ b/Source/WarpX.cpp
@@ -88,7 +88,6 @@ using namespace amrex;
 Vector<Real> WarpX::E_external_grid(3, 0.0);
 Vector<Real> WarpX::B_external_grid(3, 0.0);
 
-std::string WarpX::authors;
 std::string WarpX::B_ext_grid_s;
 std::string WarpX::E_ext_grid_s;
 bool WarpX::add_external_E_field = false;