diff --git a/re.c b/re.c
index 5d365edb63..96a3cbeaa9 100644
--- a/re.c
+++ b/re.c
@@ -1829,6 +1829,9 @@ rb_reg_search_set_match(VALUE re, VALUE str, long pos, int reverse, int set_back
     if (NIL_P(match)) {
         match = match_alloc(rb_cMatch);
     }
+    else {
+        onig_region_free(&RMATCH_EXT(match)->regs, false);
+    }
 
     rb_matchext_t *rm = RMATCH_EXT(match);
     rm->regs = regs;
diff --git a/test/ruby/test_regexp.rb b/test/ruby/test_regexp.rb
index f22128686e..be7c6761ca 100644
--- a/test/ruby/test_regexp.rb
+++ b/test/ruby/test_regexp.rb
@@ -999,6 +999,18 @@ class TestRegexp < Test::Unit::TestCase
     assert_equal('foobazquux/foobazquux', result, bug8856)
   end
 
+  def test_regsub_no_memory_leak
+    assert_no_memory_leak([], "#{<<~"begin;"}", "#{<<~"end;"}", rss: true)
+      code = proc do
+        "aaaaaaaaaaa".gsub(/a/, "")
+      end
+
+      1_000.times(&code)
+    begin;
+      100_000.times(&code)
+    end;
+  end
+
   def test_ignorecase
     v = assert_deprecated_warning(/variable \$= is no longer effective/) { $= }
     assert_equal(false, v)