diff --git a/macros/src/component/coupled/components.rs b/macros/src/component/coupled/components.rs
index 4811721..10a6ae7 100644
--- a/macros/src/component/coupled/components.rs
+++ b/macros/src/component/coupled/components.rs
@@ -9,7 +9,7 @@ use syn::{
 
 pub struct Component {
     pub ident: Ident,
-    pub colon: Token![:],
+    pub _colon: Token![:],
     pub ty: Type,
 }
 
@@ -18,12 +18,16 @@ impl Parse for Component {
         let ident = input.parse()?;
         let colon = input.parse()?;
         let ty = input.parse()?;
-        Ok(Self { ident, colon, ty })
+        Ok(Self {
+            ident,
+            _colon: colon,
+            ty,
+        })
     }
 }
 
 pub struct Components {
-    pub brace: Brace,
+    pub _brace: Brace,
     pub components: Vec<Component>,
 }
 
@@ -71,6 +75,9 @@ impl Parse for Components {
             }
         }
 
-        Ok(Self { brace, components })
+        Ok(Self {
+            _brace: brace,
+            components,
+        })
     }
 }
diff --git a/macros/src/component/coupled/coupling.rs b/macros/src/component/coupled/coupling.rs
index f5309c4..ac02438 100644
--- a/macros/src/component/coupled/coupling.rs
+++ b/macros/src/component/coupled/coupling.rs
@@ -94,7 +94,7 @@ impl Parse for Coupling {
 }
 
 pub struct Couplings {
-    pub brace: Brace,
+    pub _brace: Brace,
     pub couplings: Vec<Coupling>,
 }
 
@@ -133,6 +133,9 @@ impl Parse for Couplings {
                 content.parse::<Token![,]>()?; // comma between meta arguments
             }
         }
-        Ok(Self { brace, couplings })
+        Ok(Self {
+            _brace: brace,
+            couplings,
+        })
     }
 }
diff --git a/src/simulator.rs b/src/simulator.rs
index ae13adb..9f77234 100644
--- a/src/simulator.rs
+++ b/src/simulator.rs
@@ -18,13 +18,13 @@ impl<M: AbstractSimulator> Simulator<M> {
     /// It provides support for real time execution via the following arguments:
     ///
     /// - `wait_until`: a closure that is called between state transitions.
-    /// It receives the time of the next state transition and a mutable reference to the input ports.
-    /// It returns the actual time "waited".
-    /// If the returned time is equal to the input time, an internal/confluent state transition is performed.
-    /// Otherwise, it assumes that an external event happened and executes the external transition function.
+    ///   It receives the time of the next state transition and a mutable reference to the input ports.
+    ///   It returns the actual time "waited".
+    ///   If the returned time is equal to the input time, an internal/confluent state transition is performed.
+    ///   Otherwise, it assumes that an external event happened and executes the external transition function.
     /// - `propagate_output`: a closure that is called after output functions.
-    /// It receives a mutable reference to the output ports so the closure can access to output events.
-    /// Feel free to ignore this argument if you do not need to propagate output messages.
+    ///   It receives a mutable reference to the output ports so the closure can access to output events.
+    ///   Feel free to ignore this argument if you do not need to propagate output messages.
     #[inline]
     pub fn simulate_rt(
         &mut self,