diff --git a/src/common/cache_control.rs b/src/common/cache_control.rs
index 58dc6a63..52766ae1 100644
--- a/src/common/cache_control.rs
+++ b/src/common/cache_control.rs
@@ -124,7 +124,7 @@ impl CacheControl {
         self.flags.contains(Flags::IMMUTABLE)
     }
 
-    /// Check if the `must_understand` directive is set.
+    /// Check if the `must_revalidate` directive is set.
     pub fn must_revalidate(&self) -> bool {
         self.flags.contains(Flags::MUST_REVALIDATE)
     }
@@ -198,7 +198,7 @@ impl CacheControl {
         self
     }
 
-    /// Set the `must_understand` directive.
+    /// Set the `must_revalidate` directive.
     pub fn with_must_revalidate(mut self) -> Self {
         self.flags.insert(Flags::MUST_REVALIDATE);
         self