diff --git a/README.md b/README.md
index be3cbce7..45c66584 100644
--- a/README.md
+++ b/README.md
@@ -47,8 +47,8 @@ This is a pure-Ruby library for working with [Resource Description Framework
   not modify any of Ruby's core classes or standard library.
 * Based entirely on Ruby's autoloading, meaning that you can generally make
   use of any one part of the library without needing to load up the rest.
-* Compatible with Ruby Ruby >= 2.4, Rubinius and JRuby 9.0+.
-  * Note, changes in mapping hashes to keyword arguments for Ruby 2.7+ may require that arguments be passed more explicitly, especially when the first argument is a Hash and there are optional keyword arguments. In this case, Hash argument may need to be explicitly included within `{}` and the optional keyword arguments may need to be specified using `**{}` if there are no keyword arguments.
+* Compatible with Ruby Ruby >= 3.0, Rubinius and JRuby 9.0+.
+  * Note, changes in mapping hashes to keyword arguments for Ruby 3+ may require that arguments be passed more explicitly, especially when the first argument is a Hash and there are optional keyword arguments. In this case, Hash argument may need to be explicitly included within `{}` and the optional keyword arguments may need to be specified using `**{}` if there are no keyword arguments.
 * Performs auto-detection of input to select appropriate Reader class if one
   cannot be determined from file characteristics.
 
diff --git a/lib/rdf/model/literal/decimal.rb b/lib/rdf/model/literal/decimal.rb
index a32ebcd8..653c201b 100644
--- a/lib/rdf/model/literal/decimal.rb
+++ b/lib/rdf/model/literal/decimal.rb
@@ -26,7 +26,7 @@ def initialize(value, datatype: nil, lexical: nil, **options)
         when value.is_a?(::Numeric)    then BigDecimal(value)
         else
           value = value.to_s
-          value += "0" if value.end_with?(".")  # Normalization required in Ruby 2.4
+          value += "0" if value.end_with?(".")
           BigDecimal(value) rescue BigDecimal(0)
       end
     end
diff --git a/lib/rdf/util/cache.rb b/lib/rdf/util/cache.rb
index 7426f8aa..355d18c8 100644
--- a/lib/rdf/util/cache.rb
+++ b/lib/rdf/util/cache.rb
@@ -110,7 +110,7 @@ def finalizer_proc
 
     ##
     # This implementation uses the `WeakRef` class from Ruby's standard
-    # library, and provides adequate performance on JRuby and on Ruby 2.x.
+    # library, and provides adequate performance on JRuby and on Ruby 3.x.
     #
     # @see http://ruby-doc.org/stdlib-2.2.0/libdoc/weakref/rdoc/WeakRef.html
     class WeakRefCache < Cache