5 files changed, 12 insertions, 15 deletions
diff --git a/ext/digest/digest.h b/ext/digest/digest.h
index 4b6954089f..0d4f0e7cc2 100644
--- a/ext/digest/digest.h
+++ b/ext/digest/digest.h
@@ -62,3 +62,11 @@ rb_id_metadata(void)
 {
     return rb_intern_const("metadata");
 }
+
+static inline VALUE
+rb_digest_make_metadata(const rb_digest_metadata_t *meta)
+{
+#undef RUBY_UNTYPED_DATA_WARNING
+#define RUBY_UNTYPED_DATA_WARNING 0
+    return rb_obj_freeze(Data_Wrap_Struct(0, 0, 0, (void *)meta));
+}
diff --git a/ext/digest/md5/md5init.c b/ext/digest/md5/md5init.c
index 688a955b69..52cba78bf1 100644
--- a/ext/digest/md5/md5init.c
+++ b/ext/digest/md5/md5init.c
@@ -57,8 +57,5 @@ Init_md5(void)
 
     cDigest_MD5 = rb_define_class_under(mDigest, "MD5", cDigest_Base);
 
-#undef RUBY_UNTYPED_DATA_WARNING
-#define RUBY_UNTYPED_DATA_WARNING 0
-    rb_iv_set(cDigest_MD5, "metadata",
-	      Data_Wrap_Struct(0, 0, 0, (void *)&md5));
+    rb_iv_set(cDigest_MD5, "metadata", rb_digest_make_metadata(&md5));
 }
diff --git a/ext/digest/rmd160/rmd160init.c b/ext/digest/rmd160/rmd160init.c
index 2c44d83df6..2ae81ec4d6 100644
--- a/ext/digest/rmd160/rmd160init.c
+++ b/ext/digest/rmd160/rmd160init.c
@@ -53,8 +53,5 @@ Init_rmd160(void)
 
     cDigest_RMD160 = rb_define_class_under(mDigest, "RMD160", cDigest_Base);
 
-#undef RUBY_UNTYPED_DATA_WARNING
-#define RUBY_UNTYPED_DATA_WARNING 0
-    rb_iv_set(cDigest_RMD160, "metadata",
-	      Data_Wrap_Struct(0, 0, 0, (void *)&rmd160));
+    rb_iv_set(cDigest_RMD160, "metadata", rb_digest_make_metadata(&rmd160));
 }
diff --git a/ext/digest/sha1/sha1init.c b/ext/digest/sha1/sha1init.c
index 1d201c51fc..f7047bc6d3 100644
--- a/ext/digest/sha1/sha1init.c
+++ b/ext/digest/sha1/sha1init.c
@@ -59,8 +59,5 @@ Init_sha1(void)
 
     cDigest_SHA1 = rb_define_class_under(mDigest, "SHA1", cDigest_Base);
 
-#undef RUBY_UNTYPED_DATA_WARNING
-#define RUBY_UNTYPED_DATA_WARNING 0
-    rb_iv_set(cDigest_SHA1, "metadata",
-	      Data_Wrap_Struct(0, 0, 0, (void *)&sha1));
+    rb_iv_set(cDigest_SHA1, "metadata", rb_digest_make_metadata(&sha1));
 }
diff --git a/ext/digest/sha2/sha2init.c b/ext/digest/sha2/sha2init.c
index aad7b655c8..6ed275eb71 100644
--- a/ext/digest/sha2/sha2init.c
+++ b/ext/digest/sha2/sha2init.c
@@ -47,9 +47,7 @@ Init_sha2(void)
     cDigest_SHA##bitlen = rb_define_class_under(mDigest, "SHA" #bitlen, cDigest_Base); \
 \
     rb_ivar_set(cDigest_SHA##bitlen, id_metadata, \
-		Data_Wrap_Struct(0, 0, 0, (void *)&sha##bitlen));
+		rb_digest_make_metadata(&sha##bitlen));
 
-#undef RUBY_UNTYPED_DATA_WARNING
-#define RUBY_UNTYPED_DATA_WARNING 0
     FOREACH_BITLEN(DEFINE_ALGO_CLASS)
 }