diff --git a/ext/readline/extconf.rb b/ext/readline/extconf.rb
index 7bba386..bd03967 100644
--- a/ext/readline/extconf.rb
+++ b/ext/readline/extconf.rb
@@ -71,6 +71,7 @@ def readline.have_type(type)
 readline.have_func("rl_refresh_line")
 readline.have_var("rl_deprep_term_function")
 readline.have_var("rl_completion_append_character")
+readline.have_var("rl_completion_quote_character")
 readline.have_var("rl_basic_word_break_characters")
 readline.have_var("rl_completer_word_break_characters")
 readline.have_var("rl_basic_quote_characters")
diff --git a/ext/readline/readline.c b/ext/readline/readline.c
index 7356b7f..cb9372e 100644
--- a/ext/readline/readline.c
+++ b/ext/readline/readline.c
@@ -1301,6 +1301,35 @@ readline_s_get_completion_append_character(VALUE self)
 #define readline_s_get_completion_append_character rb_f_notimplement
 #endif
 
+#ifdef HAVE_RL_COMPLETION_QUOTE_CHARACTER
+/*
+ * call-seq:
+ *   Readline.completion_quote_character -> char
+ *
+ * When called during a completion (e.g. from within your completion_proc),
+ * it will return a string containing the chracter used to quote the
+ * argument being completed, or nil if the argument is unquoted.
+ *
+ * When called at other times, it will always return nil.
+ *
+ * Note that ``Readline.completer_quote_characters`` must be set,
+ * or this method will always return nil.
+ */
+static VALUE
+readline_s_get_completion_quote_character(VALUE self)
+{
+    char buf[1];
+
+    if (rl_completion_quote_character == '\0')
+        return Qnil;
+
+    buf[0] = (char) rl_completion_quote_character;
+    return rb_locale_str_new(buf, 1);
+}
+#else
+#define readline_s_get_completion_quote_character rb_f_notimplement
+#endif
+
 #ifdef HAVE_RL_BASIC_WORD_BREAK_CHARACTERS
 /*
  * call-seq:
@@ -1956,6 +1985,8 @@ Init_readline(void)
                                readline_s_set_completion_append_character, 1);
     rb_define_singleton_method(mReadline, "completion_append_character",
                                readline_s_get_completion_append_character, 0);
+    rb_define_singleton_method(mReadline, "completion_quote_character",
+                               readline_s_get_completion_quote_character, 0);
     rb_define_singleton_method(mReadline, "basic_word_break_characters=",
                                readline_s_set_basic_word_break_characters, 1);
     rb_define_singleton_method(mReadline, "basic_word_break_characters",
diff --git a/test/readline/test_readline.rb b/test/readline/test_readline.rb
index f50eafd..3bddb6e 100644
--- a/test/readline/test_readline.rb
+++ b/test/readline/test_readline.rb
@@ -550,6 +550,65 @@ def test_using_quoting_detection_proc_with_multibyte_input
     Readline.completer_word_break_characters = saved_completer_word_break_characters
   end
 
+  def test_completion_quote_character_completing_unquoted_argument
+    return unless Readline.respond_to?(:completion_quote_character)
+
+    quote_character = "original value"
+    Readline.completion_proc = -> (_) do
+      quote_character = Readline.completion_quote_character
+      []
+    end
+    Readline.completer_quote_characters = "'\""
+
+    with_temp_stdio do |stdin, stdout|
+      replace_stdio(stdin.path, stdout.path) do
+        stdin.write("input\t")
+        stdin.flush
+        Readline.readline("> ", false)
+      end
+    end
+
+    assert_nil(quote_character)
+  end
+
+  def test_completion_quote_character_completing_quoted_argument
+    return unless Readline.respond_to?(:completion_quote_character)
+
+    quote_character = "original value"
+    Readline.completion_proc = -> (_) do
+      quote_character = Readline.completion_quote_character
+      []
+    end
+    Readline.completer_quote_characters = "'\""
+
+    with_temp_stdio do |stdin, stdout|
+      replace_stdio(stdin.path, stdout.path) do
+        stdin.write("'input\t")
+        stdin.flush
+        Readline.readline("> ", false)
+      end
+    end
+
+    assert_equal("'", quote_character)
+  end
+
+  def test_completion_quote_character_after_completion
+    return unless Readline.respond_to?(:completion_quote_character)
+
+    Readline.completion_proc = -> (_) { [] }
+    Readline.completer_quote_characters = "'\""
+
+    with_temp_stdio do |stdin, stdout|
+      replace_stdio(stdin.path, stdout.path) do
+        stdin.write("'input\t")
+        stdin.flush
+        Readline.readline("> ", false)
+      end
+    end
+
+    assert_nil(Readline.completion_quote_character)
+  end
+
   private
 
   def replace_stdio(stdin_path, stdout_path)