diff --git a/lib/reline/io/ansi.rb b/lib/reline/io/ansi.rb
index 4fd0023259..c51e97b722 100644
--- a/lib/reline/io/ansi.rb
+++ b/lib/reline/io/ansi.rb
@@ -38,6 +38,9 @@ def initialize
 
   def encoding
     @input.external_encoding || Encoding.default_external
+  rescue IOError
+    # STDIN.external_encoding raises IOError in Ruby <= 3.0 when STDIN is closed
+    Encoding.default_external
   end
 
   def set_default_key_bindings(config)
diff --git a/lib/reline/io/dumb.rb b/lib/reline/io/dumb.rb
index 34bba98ba1..e58ba0f6d8 100644
--- a/lib/reline/io/dumb.rb
+++ b/lib/reline/io/dumb.rb
@@ -21,8 +21,11 @@ def encoding
     elsif RUBY_PLATFORM =~ /mswin|mingw/
       Encoding::UTF_8
     else
-      @input.external_encoding || Encoding::default_external
+      @input.external_encoding || Encoding.default_external
     end
+  rescue IOError
+    # STDIN.external_encoding raises IOError in Ruby <= 3.0 when STDIN is closed
+    Encoding.default_external
   end
 
   def set_default_key_bindings(_)