diff --git a/lib/lograge/formatters/graylog2.rb b/lib/lograge/formatters/graylog2.rb
index 82a6a869..84f4d486 100644
--- a/lib/lograge/formatters/graylog2.rb
+++ b/lib/lograge/formatters/graylog2.rb
@@ -13,7 +13,7 @@ def call(data)
       end
 
       def underscore_prefix(key)
-        "_#{key}".to_sym
+        :"_#{key}"
       end
 
       def short_message(data)
diff --git a/lib/lograge/formatters/key_value_deep.rb b/lib/lograge/formatters/key_value_deep.rb
index bee43e25..704bcafd 100644
--- a/lib/lograge/formatters/key_value_deep.rb
+++ b/lib/lograge/formatters/key_value_deep.rb
@@ -4,7 +4,7 @@ module Lograge
   module Formatters
     class KeyValueDeep < KeyValue
       def call(data)
-        super flatten_keys(data)
+        super(flatten_keys(data))
       end
 
       protected
diff --git a/lib/lograge/log_subscribers/base.rb b/lib/lograge/log_subscribers/base.rb
index 46cc7a30..a9c26557 100644
--- a/lib/lograge/log_subscribers/base.rb
+++ b/lib/lograge/log_subscribers/base.rb
@@ -61,7 +61,7 @@ def get_error_status_code(exception_class_name)
       end
 
       def extract_allocations(event)
-        if (allocations = (event.respond_to?(:allocations) && event.allocations))
+        if (allocations = event.respond_to?(:allocations) && event.allocations)
           { allocations: allocations }
         else
           {}