diff --git a/Eigen/src/Core/util/XprHelper.h b/Eigen/src/Core/util/XprHelper.h
index eb7f30ced..622c84a8e 100644
--- a/Eigen/src/Core/util/XprHelper.h
+++ b/Eigen/src/Core/util/XprHelper.h
@@ -28,7 +28,13 @@
 
 // just a workaround because GCC seems to not really like empty structs
 #ifdef __GNUG__
-  class ei_empty_struct{char _ei_dummy_;};
+  struct ei_empty_struct
+  {
+    EIGEN_ALWAYS_INLINE_ATTRIB ei_empty_struct() {}
+    EIGEN_ALWAYS_INLINE_ATTRIB ei_empty_struct(const ei_empty_struct&) {}
+    EIGEN_ALWAYS_INLINE_ATTRIB ei_empty_struct& operator=(const ei_empty_struct&) { return *this; }
+    char _ei_dummy_;
+  };
   #define EIGEN_EMPTY_STRUCT : Eigen::ei_empty_struct
 #else
   #define EIGEN_EMPTY_STRUCT