diff --git a/src/rstd/inlining.rs b/src/rstd/inlining.rs
index 7a5af27..54e7b11 100644
--- a/src/rstd/inlining.rs
+++ b/src/rstd/inlining.rs
@@ -88,8 +88,8 @@ impl<'a: 'c, 'c, Ctx: Context<'a>> InCtx<'a, Ctx> for &'c mut dyn DeCtx<'a, Ctx>
     }
 }
 
-pub trait InliningDyn: Sized {
-    fn idread_n(self, n: usize) -> Result<(Vec<u8>, Self), Vec<u8>>;
+pub trait InliningDyn {
+    fn idread_n(self, n: usize) -> Result<(Vec<u8>, Box<Self>), Vec<u8>>;
 
     fn idread_all(self) -> Vec<u8>;
 
@@ -97,8 +97,9 @@ pub trait InliningDyn: Sized {
 }
 
 impl<I: Inlining> InliningDyn for I {
-    fn idread_n(self, n: usize) -> Result<(Vec<u8>, Self), Vec<u8>> {
-        self.iread_n(n, |slice| Vec::from(slice), |slice| Vec::from(slice))
+    fn idread_n(self, n: usize) -> Result<(Vec<u8>, Box<Self>), Vec<u8>> {
+        let (vec, i) = self.iread_n(n, |slice| Vec::from(slice), |slice| Vec::from(slice))?;
+        Ok((vec, i.into()))
     }
 
     fn idread_all(self) -> Vec<u8> {