diff --git a/regparse.c b/regparse.c
index 1ce15da8f5..57ecd78dee 100644
--- a/regparse.c
+++ b/regparse.c
@@ -6105,7 +6105,8 @@ node_extended_grapheme_cluster(Node** np, ScanEnv* env)
           R_ERR(add_code_range(&(cc->mbuf), env, 0x000A, 0x000A)); /* CR */
           R_ERR(add_code_range(&(cc->mbuf), env, 0x000D, 0x000D)); /* LF */
           R_ERR(not_code_range_buf(env->enc, cc->mbuf, &inverted_buf, env));
-          cc->mbuf = inverted_buf; /* TODO: check what to do with buffer before inversion */
+          bbuf_free(cc->mbuf);
+          cc->mbuf = inverted_buf;
 
           env->warnings_flag &= dup_not_warned; /* TODO: fix false warning */
         }
diff --git a/version.h b/version.h
index 39717974d2..bdeb9f6ab6 100644
--- a/version.h
+++ b/version.h
@@ -11,7 +11,7 @@
 # define RUBY_VERSION_MINOR RUBY_API_VERSION_MINOR
 #define RUBY_VERSION_TEENY 0
 #define RUBY_RELEASE_DATE RUBY_RELEASE_YEAR_STR"-"RUBY_RELEASE_MONTH_STR"-"RUBY_RELEASE_DAY_STR
-#define RUBY_PATCHLEVEL 12
+#define RUBY_PATCHLEVEL 13
 
 #include "ruby/version.h"
 #include "ruby/internal/abi.h"