diff --git a/boa_engine/src/environments/runtime/mod.rs b/boa_engine/src/environments/runtime/mod.rs
index 1c2b284b87f..f873dfd95f0 100644
--- a/boa_engine/src/environments/runtime/mod.rs
+++ b/boa_engine/src/environments/runtime/mod.rs
@@ -672,7 +672,11 @@ impl Context<'_> {
         }
     }
 
-    /// Return the environment at the given index. Panics if the index is out of range.
+    /// Return the environment at the given index.
+    ///
+    /// # Panics
+    ///
+    /// Panics if the `index` is out of range.
     pub(crate) fn environment_expect(&self, index: u32) -> &Environment {
         self.vm
             .environments
diff --git a/boa_engine/src/vm/code_block.rs b/boa_engine/src/vm/code_block.rs
index 86461a758fb..0e4a000bb26 100644
--- a/boa_engine/src/vm/code_block.rs
+++ b/boa_engine/src/vm/code_block.rs
@@ -251,31 +251,49 @@ impl CodeBlock {
             .find(|(_, handler)| handler.contains(pc))
     }
 
+    /// Get the [`JsString`] constant from the [`CodeBlock`].
+    ///
+    /// # Panics
+    ///
+    /// If the type of the [`Constant`] is not [`Constant::String`].
+    /// Or `index` is greater or equal to length of `constants`.
     pub(crate) fn constant_string_expect(&self, index: usize) -> JsString {
-        if let Constant::String(value) = &self.constants[index] {
+        if let Some(Constant::String(value)) = self.constants.get(index) {
             return value.clone();
         }
 
-        panic!("there should be a string constant at index {index}")
+        panic!("expected string constant at index {index}")
     }
 
+    /// Get the function ([`Gc<CodeBlock>`]) constant from the [`CodeBlock`].
+    ///
+    /// # Panics
+    ///
+    /// If the type of the [`Constant`] is not [`Constant::Function`].
+    /// Or `index` is greater or equal to length of `constants`.
     pub(crate) fn constant_function_expect(&self, index: usize) -> Gc<Self> {
-        if let Constant::Function(value) = &self.constants[index] {
+        if let Some(Constant::Function(value)) = self.constants.get(index) {
             return value.clone();
         }
 
-        panic!("there should be a function constant at index {index}")
+        panic!("expected function constant at index {index}")
     }
 
+    /// Get the [`CompileTimeEnvironment`] constant from the [`CodeBlock`].
+    ///
+    /// # Panics
+    ///
+    /// If the type of the [`Constant`] is not [`Constant::CompileTimeEnvironment`].
+    /// Or `index` is greater or equal to length of `constants`.
     pub(crate) fn constant_compile_time_environment_expect(
         &self,
         index: usize,
     ) -> Rc<CompileTimeEnvironment> {
-        if let Constant::CompileTimeEnvironment(value) = &self.constants[index] {
+        if let Some(Constant::CompileTimeEnvironment(value)) = self.constants.get(index) {
             return value.clone();
         }
 
-        panic!("there should be a compile time environment constant at index {index}")
+        panic!("expected compile time environment constant at index {index}")
     }
 }