diff --git a/src/func/context.rs b/src/func/context.rs
index ef74a95..2042b33 100644
--- a/src/func/context.rs
+++ b/src/func/context.rs
@@ -40,3 +40,7 @@ pub trait FunctorContextExt<'a>: FunctorContext<'a> {
 }
 
 impl<'a, Ctx: FunctorContext<'a>> FunctorContextExt<'a> for Ctx {}
+
+trait FallibleCtx<'a>: FunctorContext<'a> {
+    type Fallible: MonadFailAny<'a, T = Self::T>;
+}