diff --git a/askama_derive/src/input.rs b/askama_derive/src/input.rs
index fe42881fd..5230a6d7a 100644
--- a/askama_derive/src/input.rs
+++ b/askama_derive/src/input.rs
@@ -133,21 +133,30 @@ impl TemplateInput<'_> {
                                 .into());
                             }
                             dependency_graph.push(dependency_path);
-                            let source = get_template_source(&extends)?;
-                            check.push((extends, source));
+                            if !map.contains_key(&extends) {
+                                map.insert(extends.clone(), Parsed::default());
+                                let source = get_template_source(&extends)?;
+                                check.push((extends, source));
+                            }
                         }
                         Node::Macro(m) if top => {
                             nested.push(&m.nodes);
                         }
                         Node::Import(import) if top => {
                             let import = self.config.find_template(import.path, Some(&path))?;
-                            let source = get_template_source(&import)?;
-                            check.push((import, source));
+                            if !map.contains_key(&import) {
+                                map.insert(import.clone(), Parsed::default());
+                                let source = get_template_source(&import)?;
+                                check.push((import, source));
+                            }
                         }
                         Node::Include(include) => {
                             let include = self.config.find_template(include.path, Some(&path))?;
-                            let source = get_template_source(&include)?;
-                            check.push((include, source));
+                            if !map.contains_key(&include) {
+                                map.insert(include.clone(), Parsed::default());
+                                let source = get_template_source(&include)?;
+                                check.push((include, source));
+                            }
                         }
                         Node::BlockDef(b) => {
                             nested.push(&b.nodes);
diff --git a/askama_parser/src/lib.rs b/askama_parser/src/lib.rs
index 4d27d7028..e6f133c37 100644
--- a/askama_parser/src/lib.rs
+++ b/askama_parser/src/lib.rs
@@ -28,6 +28,7 @@ mod _parsed {
     use super::node::Node;
     use super::{Ast, ParseError, Syntax};
 
+    #[derive(Default)]
     pub struct Parsed {
         // `source` must outlive `ast`, so `ast` must be declared before `source`
         ast: Ast<'static>,
@@ -68,7 +69,7 @@ mod _parsed {
 
 pub use _parsed::Parsed;
 
-#[derive(Debug)]
+#[derive(Debug, Default)]
 pub struct Ast<'a> {
     nodes: Vec<Node<'a>>,
 }