diff --git a/codegen/src/json.rs b/codegen/src/json.rs
index 668c507..63764b6 100644
--- a/codegen/src/json.rs
+++ b/codegen/src/json.rs
@@ -4,7 +4,9 @@
 use std::path::Path;
 
 pub fn generate(defs: &Definitions) {
-    let j = serde_json::to_string_pretty(&defs).unwrap();
+    let mut j = serde_json::to_string_pretty(&defs).unwrap();
+    j.push('\n');
+
     let check: Definitions = serde_json::from_str(&j).unwrap();
     assert_eq!(*defs, check);
 
diff --git a/syn.json b/syn.json
index f94e9aa..7555b1c 100644
--- a/syn.json
+++ b/syn.json
@@ -5830,4 +5830,4 @@
     "While": "while",
     "Yield": "yield"
   }
-}
\ No newline at end of file
+}