diff --git a/README.md b/README.md
index 2779d8c..cc7a4b7 100644
--- a/README.md
+++ b/README.md
@@ -268,7 +268,7 @@ use evalexpr::*;
 
 let context = context_map!{
     "f" => Function::new(Box::new(|args| Ok(Value::from(args.as_int()? + 5)))),
-};
+}.unwrap_or_else(|error| panic!("Error creating context: {}", error));
 assert_eq!(eval_int_with_context("f 5", &context), Ok(10));
 ```
 
diff --git a/src/lib.rs b/src/lib.rs
index 3cc08e7..c0c18c2 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -255,7 +255,7 @@
 //!
 //! let context = context_map!{
 //!     "f" => Function::new(Box::new(|args| Ok(Value::from(args.as_int()? + 5)))),
-//! };
+//! }.unwrap_or_else(|error| panic!("Error creating context: {}", error));
 //! assert_eq!(eval_int_with_context("f 5", &context), Ok(10));
 //! ```
 //!