diff --git a/src/rcore/modes.rs b/src/rcore/modes.rs
index cf8eb40..0286d49 100644
--- a/src/rcore/modes.rs
+++ b/src/rcore/modes.rs
@@ -14,6 +14,8 @@ pub trait Mode {
         result: Self::ParseResult<A0, E, I>,
         f: impl FnOnce(A0) -> Result<A1, E>,
     ) -> Self::ParseResult<A1, E, I>;
+
+    fn seal<A, E, I>(result: Self::ParseResult<A, E, I>) -> Result<A, E>;
 }
 
 pub trait ParseMode {
@@ -79,6 +81,10 @@ impl Mode for RegularMode {
     ) -> Self::ParseResult<A1, E, I> {
         result.and_then(f)
     }
+
+    fn seal<A, E, I>(result: Self::ParseResult<A, E, I>) -> Result<A, E> {
+        result
+    }
 }
 
 pub trait RegularFactory<'a, Ctx: Context<'a>>:
diff --git a/src/rstd/inlining/modes.rs b/src/rstd/inlining/modes.rs
index 7ac123b..10f3d95 100644
--- a/src/rstd/inlining/modes.rs
+++ b/src/rstd/inlining/modes.rs
@@ -20,6 +20,10 @@ impl Mode for InliningMode {
         let a1 = f(a0)?;
         Ok((a1, i))
     }
+
+    fn seal<A, E, I>(result: Self::ParseResult<A, E, I>) -> Result<A, E> {
+        result.map(|(a, _)| a)
+    }
 }
 
 impl<'a, Ctx: Context<'a>, F: InlineableFactory<'a, Ctx>> FactoryProxy<'a, Ctx>