diff --git a/config/ameba.yml b/config/ameba.yml
index 63416a42..934194dd 100644
--- a/config/ameba.yml
+++ b/config/ameba.yml
@@ -1,4 +1,4 @@
-ComaprisonToBoolean:
+ComparisonToBoolean:
   # Disallows comparison to booleans in conditions.
   Enabled: true
 
@@ -10,6 +10,10 @@ DebuggerStatement:
   # Disallows calls to debugger.
   Enabled: true
 
+DuplicatedWhen:
+  # Disallows duplicated when conditions in case.
+  Enabled: true
+
 EmptyEnsure:
   # Disallows empty ensure statement.
   Enabled: true
diff --git a/src/ameba/config.cr b/src/ameba/config.cr
index cbd2179a..4263ba6f 100644
--- a/src/ameba/config.cr
+++ b/src/ameba/config.cr
@@ -60,8 +60,8 @@ class Ameba::Config
     @formatter ||= default_formatter
   end
 
-  # Returns a subconfig of a home full loaded configuration.
-  # This is used to get a corresponding to a specific rule config.
+  # Returns a subconfig of a fully loaded configuration.
+  # This is used to get a config for a specific rule.
   #
   # ```
   # config = Ameba::Config.load