diff --git a/src/how.rs b/src/how.rs
index 6dbbd4d..33ebd80 100644
--- a/src/how.rs
+++ b/src/how.rs
@@ -35,7 +35,7 @@ impl How {
             classified: false,
             context: {
                 let mut vec = Vec::with_capacity(4);
-                vec[0] = context.into_context();
+                vec.push(context.into_context());
                 vec
             },
             #[cfg(feature = "backtrace")]