1 files changed, 6 insertions, 0 deletions
diff --git a/include/gras/gras.hpp b/include/gras/gras.hpp
index 6d1808b..c809f45 100644
--- a/include/gras/gras.hpp
+++ b/include/gras/gras.hpp
@@ -70,6 +70,12 @@ namespace gras
 {
     //! Typedef for absolute item indexes
     typedef unsigned long long item_index_t;
+
+    //! Forward declare for element base class
+    struct ElementImpl;
+
+    //! Forward declare for block class
+    struct Block;
 }
 
 #endif /*INCLUDED_GRAS_GRAS_HPP*/