diff --git a/src/lib.rs b/src/lib.rs
index 4dbd814..1c3377e 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -10,7 +10,7 @@ use std::{
 pub struct Malestorm<'a> {
     node: RefCell<Node>,
     io: MalestormIo,
-    pub handlers: HashMap<&'a str, Box<dyn Fn(Message, Rc<Malestorm>)>>,
+    pub handlers: HashMap<&'a str, Box<dyn Fn(Message, Rc<Malestorm>) -> Result<(), String>>>,
 }
 
 struct Node {
@@ -96,7 +96,9 @@ impl<'a> Malestorm<'a> {
                 }
             };
 
-            handler(message, pc);
+            if let Err(e) = handler(message, pc) {
+                eprintln!("error in serving request: {}", e);
+            }
         }
     }
 
@@ -113,7 +115,7 @@ impl<'a> Malestorm<'a> {
     pub fn register(
         &mut self,
         name: &'a str,
-        func: impl Fn(Message, Rc<Malestorm>) + 'a + 'static,
+        func: impl Fn(Message, Rc<Malestorm>) -> Result<(), String> + 'a + 'static,
     ) {
         self.handlers.insert(name, Box::new(func));
     }
diff --git a/src/main.rs b/src/main.rs
index 8da0f75..58a748b 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -7,37 +7,38 @@ use std::rc::Rc;
 fn main() {
     let mut program = Malestorm::default();
 
-    program.register("init", |mut msg: Message, program: Rc<Malestorm>| {
-        let message_body: InitMessage = serde_json::from_value(msg.body.message_body.take())
-            .expect("error in parsing message body");
+    program.register(
+        "init",
+        // TODO: Replace error string with a type
+        |mut msg: Message, program: Rc<Malestorm>| -> Result<(), String> {
+            let message_body: InitMessage = serde_json::from_value(msg.body.message_body.take())
+                .map_err(|e| format!("error in parsing response body: {}", e))?;
 
-        program.set_node_id(message_body.node_id);
-        program.set_nodes(message_body.nodes);
+            program.set_node_id(message_body.node_id);
+            program.set_nodes(message_body.nodes);
 
-        msg.body.message_type = "init_ok".into();
+            msg.body.message_type = "init_ok".into();
 
-        match program.reply(msg) {
-            Ok(_) => (),
-            Err(e) => {
-                eprintln!("init: error in writing response: {}", e);
-            }
-        }
-    });
+            program
+                .reply(msg)
+                .map_err(|e| format!("init: error in writing response: {}", e))
+        },
+    );
 
-    program.register("echo", |mut msg: Message, program: Rc<Malestorm>| {
-        let message_body: EchoMessage = serde_json::from_value(msg.body.message_body.take())
-            .expect("error in parsing message body");
+    program.register(
+        "echo",
+        |mut msg: Message, program: Rc<Malestorm>| -> Result<(), String> {
+            let message_body: EchoMessage = serde_json::from_value(msg.body.message_body.take())
+                .map_err(|e| format!("error in parsing response body: {}", e))?;
 
-        msg.body.message_type = "echo_ok".into();
-        msg.body.message_body = serde_json::to_value(message_body).unwrap();
+            msg.body.message_type = "echo_ok".into();
+            msg.body.message_body = serde_json::to_value(message_body).unwrap();
 
-        match program.reply(msg) {
-            Ok(_) => (),
-            Err(e) => {
-                eprintln!("echo: error in writing response: {}", e);
-            }
-        }
-    });
+            program
+                .reply(msg)
+                .map_err(|e| format!("echo: error in writing response: {}", e))
+        },
+    );
 
     program.run();
 }