1 files changed, 4 insertions, 0 deletions
diff --git a/src/flatten.cpp b/src/flatten.cpp
index 8d92ff9..424e5a6 100644
--- a/src/flatten.cpp
+++ b/src/flatten.cpp
@@ -65,6 +65,10 @@ static const AST*
 flatten_def_type(CEnv& cenv, Code& code, const ATuple* def) throw()
 {
 	const ASymbol* name = def->frst()->to_symbol();
+	if (!def->rrst()) {  // Forward declaration
+		code.push_back(def);
+		return NULL;
+	}
 	if (name) {
 		cenv.tenv.def(name, def->frrst());
 	} else {