1 files changed, 2 insertions, 2 deletions
diff --git a/toml/parser.ts b/toml/parser.ts
index c29f5a761..c615c3c1e 100644
--- a/toml/parser.ts
+++ b/toml/parser.ts
@@ -399,12 +399,12 @@ class Dumper {
     const out = [];
     const props = Object.keys(obj);
     const propObj = props.filter(
-      e =>
+      (e): boolean =>
         (obj[e] instanceof Array && !this._isSimplySerializable(obj[e][0])) ||
         !this._isSimplySerializable(obj[e])
     );
     const propPrim = props.filter(
-      e =>
+      (e): boolean =>
         !(obj[e] instanceof Array && !this._isSimplySerializable(obj[e][0])) &&
         this._isSimplySerializable(obj[e])
     );