diff --git a/src/protocol/ast_printer.rs b/src/protocol/ast_printer.rs
index 4e566cdc23d634459b11530513dee8b50d57f704..6aff2810101c2a5143012ad83ec80eaa21cd852d 100644
--- a/src/protocol/ast_printer.rs
+++ b/src/protocol/ast_printer.rs
@@ -36,6 +36,8 @@ const PREFIX_BREAK_STMT_ID: &'static str = "SBre";
 const PREFIX_CONTINUE_STMT_ID: &'static str = "SCon";
 const PREFIX_SYNC_STMT_ID: &'static str = "SSyn";
 const PREFIX_ENDSYNC_STMT_ID: &'static str = "SESy";
+const PREFIX_FORK_STMT_ID: &'static str = "SFrk";
+const PREFIX_END_FORK_STMT_ID: &'static str = "SEFk";
 const PREFIX_RETURN_STMT_ID: &'static str = "SRet";
 const PREFIX_ASSERT_STMT_ID: &'static str = "SAsr";
 const PREFIX_GOTO_STMT_ID: &'static str = "SGot";
@@ -511,6 +513,24 @@ impl ASTWriter {
                 self.kv(indent2).with_s_key("StartSync").with_disp_val(&stmt.start_sync.0.index);
                 self.kv(indent2).with_s_key("Next").with_disp_val(&stmt.next.index);
             },
+            Statement::Fork(stmt) => {
+                self.kv(indent).with_id(PREFIX_FORK_STMT_ID, stmt.this.0.index)
+                    .with_s_key("Fork");
+                self.kv(indent2).with_s_key("EndFork").with_disp_val(&stmt.end_fork.0.index);
+                self.kv(indent2).with_s_key("LeftBody");
+                self.write_stmt(heap, stmt.left_body.upcast(), indent3);
+
+                if let Some(right_body_id) = stmt.right_body {
+                    self.kv(indent2).with_s_key("RightBody");
+                    self.write_stmt(heap, right_body_id.upcast(), indent3);
+                }
+            },
+            Statement::EndFork(stmt) => {
+                self.kv(indent).with_id(PREFIX_END_FORK_STMT_ID, stmt.this.0.index)
+                    .with_s_key("EndFork");
+                self.kv(indent2).with_s_key("StartFork").with_disp_val(&stmt.start_fork.0.index);
+                self.kv(indent2).with_s_key("Next").with_disp_val(&stmt.next.index);
+            }
             Statement::Return(stmt) => {
                 self.kv(indent).with_id(PREFIX_RETURN_STMT_ID, stmt.this.0.index)
                     .with_s_key("Return");